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Sample records for activates toll-like receptor

  1. DMPD: Proximal effects of Toll-like receptor activation in dendritic cells. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17142025 Proximal effects of Toll-like receptor activation in dendritic cells. Watt...) (.svg) (.html) (.csml) Show Proximal effects of Toll-like receptor activation in dendritic cells. PubmedID... 17142025 Title Proximal effects of Toll-like receptor activation in dendritic ce

  2. The phosphoproteome of toll-like receptor-activated macrophages

    Weintz, Gabriele; Olsen, Jesper Velgaard; Frühauf, Katja;

    2010-01-01

    Recognition of microbial danger signals by toll-like receptors (TLR) causes re-programming of macrophages. To investigate kinase cascades triggered by the TLR4 ligand lipopolysaccharide (LPS) on systems level, we performed a global, quantitative and kinetic analysis of the phosphoproteome of...... identified 1850 phosphoproteins with 6956 phosphorylation sites, two thirds of which were not reported earlier. LPS caused major dynamic changes in the phosphoproteome (24% up-regulation and 9% down-regulation). Functional bioinformatic analyses confirmed canonical players of the TLR pathway and highlighted...... other signalling modules (e.g. mTOR, ATM/ATR kinases) and the cytoskeleton as hotspots of LPS-regulated phosphorylation. Finally, weaving together phosphoproteome and nascent transcriptome data by in silico promoter analysis, we implicated several phosphorylated TFs in primary LPS-controlled gene...

  3. Hypothermia Reduces Toll-Like Receptor 3-Activated Microglial Interferon-β and Nitric Oxide Production

    Tomohiro Matsui; Yukari Motoki; Yusuke Yoshida

    2013-01-01

    Therapeutic hypothermia protects neurons after injury to the central nervous system (CNS). Microglia express toll-like receptors (TLRs) that play significant roles in the pathogenesis of sterile CNS injury. To elucidate the possible mechanisms involved in the neuroprotective effect of therapeutic hypothermia, we examined the effects of hypothermic culture on TLR3-activated microglial release of interferon (IFN)- β and nitric oxide (NO), which are known to be associated with neuronal cell deat...

  4. Murine retroviruses activate B cells via interaction with toll-like receptor 4

    Rassa, John C.; Meyers, Jennifer L.; Zhang, Yuanming; Kudaravalli, Rama; Susan R Ross

    2002-01-01

    Although most retroviruses require activated cells as their targets for infection, it is not known how this is achieved in vivo. A candidate protein for the activation of B cells by either mouse mammary tumor virus (MMTV) or murine leukemia virus is the toll-like receptor 4 (TLR4), a component of the innate immune system. MMTV caused B cell activation in C3H/HeN mice but not in C3H/HeJ or BALB/c (C.C3H Tlr4lps-d) congenic mice, both of which have a mutant TLR4 gene. This activation was indepe...

  5. Proteolytic cleavage in an endolysosomal compartment is required for Toll-like receptor 9 activation

    Park, Boyoun; Brinkmann, Melanie M.; Spooner, Eric; Lee, Clarissa C.; Kim, You-Me; Ploegh, Hidde L.

    2008-01-01

    Toll-like receptors (TLRs) activate the innate immune system in response to pathogens. Here we showed that TLR9 proteolytic cleavage is a prerequisite for TLR9 signaling. Inhibition of lysosomal proteolysis rendered TLR9 inactive. The C-terminal fragment of TLR9 thus generated included a portion of the TLR9 ectodomain, as well as the transmembrane and cytoplasmic domains. This cleavage fragment bound to the TLR9 ligand CpG, and, when expressed in Tlr9−/− dendritic cells, restored CpG-induced ...

  6. Counteracting Interactions between Lipopolysaccharide Molecules with Differential Activation of Toll-Like Receptors

    Hajishengallis, George; Martin, Michael; Schifferle, Robert E.; Genco, Robert J.

    2002-01-01

    We investigated counteracting interactions between the lipopolysaccharides (LPS) from Escherichia coli (Ec-LPS) and Porphyromonas gingivalis (Pg-LPS), which induce cellular activation through Toll-like receptor 4 (TLR4) and TLR2, respectively. We found that Ec-LPS induced tolerance in THP-1 cells to subsequent tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) induction by Pg-LPS, though the reverse was not true, and looked for explanatory differential effects on the signal tr...

  7. Nuclear Factor-κB: Activation and Regulation during Toll-like Receptor Signaling

    Ruaidhrí J. Carmody; Youhai H. Chen

    2007-01-01

    Toll-like receptors (TLRs) recognize distinct microbial components to initiate the innate and adaptive immune responses. TLR activation culminates in the expression of appropriate pro-inflammatory and immunomodulatory factors to meet pathogenic challenges. The transcription factor NF-κB is the master regulator of all TLR-induced responses and its activation is the pivotal event in TLR-mediated activation of the innate immune response. Many of the key molecular events required for TLR-induced NF-κB activation have been elucidated. However, much remain to be learned about the ability of TLRs to generate pathogen-specific responses using a limited number of transcription factors. This review will focus on our current understanding of NF-κB activation by TLRs and potential mechanisms for achieving a signal-specific response through NF-κB.

  8. HIGH GLUCOSE INDUCES TOLL-LIKE RECEPTOR EXPRESSION IN HUMAN MONOCYTES: MECHANISM OF ACTIVATION

    Objective: Hyperglycemia induced inflammation is central in diabetes complications and monocytes are important in orchestrating these effects. Toll-like receptors (TLRs) play a key role in innate immune responses as well as inflammation. However, there is a paucity of data examining the expression a...

  9. Murine retroviruses activate B cells via interaction with toll-like receptor 4

    Rassa, John C.; Meyers, Jennifer L.; Zhang, Yuanming; Kudaravalli, Rama; Ross, Susan R.

    2002-01-01

    Although most retroviruses require activated cells as their targets for infection, it is not known how this is achieved in vivo. A candidate protein for the activation of B cells by either mouse mammary tumor virus (MMTV) or murine leukemia virus is the toll-like receptor 4 (TLR4), a component of the innate immune system. MMTV caused B cell activation in C3H/HeN mice but not in C3H/HeJ or BALB/c (C.C3H Tlr4lps-d) congenic mice, both of which have a mutant TLR4 gene. This activation was independent of viral gene expression, because it occurred after treatment of MMTV with ultraviolet light or 2,2′-dithiodipyridine and in azidothymidine-treated mice. Nuclear extracts prepared from the lymphocytes of MMTV-injected C3H/HeN but not C3H/HeJ mice showed increased nuclear factor κB activity. Additionally, the MMTV- and Moloney murine leukemia virus envelope proteins coimmunoprecipitated with TLR4 when expressed in 293T cells. The MMTV receptor failed to coimmunoprecipitate with TLR4, suggesting that MMTV/TLR4 interaction is independent of virus attachment and fusion. These results identify retroviral proteins that interact with a mammalian toll receptor and show that direct activation by such viruses may initiate in vivo infection pathways. PMID:11854525

  10. Toll-like receptors in neonatal sepsis.

    O'Hare, Fiona M

    2013-06-01

    Toll-like receptors are vital transmembrane receptors that initiate the innate immune response to many micro-organisms. The discovery of these receptors has improved our understanding of host-pathogen interactions, and these receptors play an important role in the pathogenesis of multiple neonatal conditions such as sepsis and brain injury. Toll-like receptors, especially TLRs 2 and 4, are associated with necrotizing enterocolitis, periventricular leukomalacia and sepsis.

  11. Toll-Like Receptor 9-Activation during Onset of Myocardial Ischemia Does Not Influence Infarct Extension

    Ohm, Ingrid Kristine; Gao, Erhe; Belland Olsen, Maria; Alfsnes, Katrine; Bliksøen, Marte; Øgaard, Jonas; Ranheim, Trine; Nymo, Ståle Haugset; Holmen, Yangchen Dhondup; Aukrust, Pål; Yndestad, Arne; Vinge, Leif Erik

    2014-01-01

    Aim Myocardial infarction (MI) remains a major cause of death and disability worldwide, despite available reperfusion therapies. Inflammatory signaling is considered nodal in defining final infarct size. Activation of the innate immune receptor toll-like receptors (TLR) 9 prior to ischemia and reperfusion (I/R) reduces infarct size, but the consequence of TLR9 activation timed to the onset of ischemia is not known. Methods and Results The TLR9-agonist; CpG B was injected i.p. in C57BL/6 mice immediately after induction of ischemia (30 minutes). Final infarct size, as well as area-at-risk, was measured after 24 hours of reperfusion. CpG B injection resulted in a significant increase in circulating granulocytes and monocytes both in sham and I/R mice. Paradoxically, clear evidence of reduced cardiac infiltration of both monocytes and granulocytes could be demonstrated in I/R mice treated with CpG B (immunocytochemistry, myeloperoxidase activity and mRNA expression patterns). In addition, systemic TLR9 activation elicited significant alterations of cardiac inflammatory genes. Despite these biochemical and cellular changes, there was no difference in infarct size between vehicle and CpG B treated I/R mice. Conclusion Systemic TLR9-stimulation upon onset of ischemia and subsequent reperfusion does not alter final infarct size despite causing clear alterations of both systemic and cardiac inflammatory parameters. Our results question the clinical usefulness of TLR9 activation during cardiac I/R. PMID:25126943

  12. Polysaccharide of Dendrobium huoshanense activates macrophages via toll-like receptor 4-mediated signaling pathways.

    Xie, Song-Zi; Hao, Ran; Zha, Xue-Qiang; Pan, Li-Hua; Liu, Jian; Luo, Jian-Ping

    2016-08-01

    The present work aimed at investigating the pattern recognition receptor (PRR) and immunostimulatory mechanism of a purified Dendrobium huoshanense polysaccharide (DHP). We found that DHP could bind to the surface of macrophages and stimulate macrophages to secrete NO, TNF-α and IL-1β. To unravel the mechanism for the binding of DHP to macrophages, flow cytometry, confocal laser-scanning microscopy, affinity electrophoresis, SDS-PAGE and western blotting were employed to verify the type of PRR responsible for the recognition of DHP by RAW264.7 macrophages and peritoneal macrophages of C3H/HeN and C3H/HeJ macrophages. Results showed that toll-like receptor 4 (TLR4) was an essential receptor for macrophages to directly bind DHP. Further, the phosphorylation of ERK, JNK, Akt and p38 were observed to be time-dependently promoted by DHP, as well as the nuclear translocation of NF-κB p65. These results suggest that DHP activates macrophages via its direct binding to TLR4 to trigger TLR4 signaling pathways. PMID:27112877

  13. Toll-like receptor 4-related immunostimulatory polysaccharides: Primary structure, activity relationships, and possible interaction models.

    Zhang, Xiaorui; Qi, Chunhui; Guo, Yan; Zhou, Wenxia; Zhang, Yongxiang

    2016-09-20

    Toll-like receptor (TLR) 4 is an important polysaccharide receptor; however, the relationships between the structures and biological activities of TLR4 and polysaccharides remain unknown. Many recent findings have revealed the primary structure of TLR4/MD-2-related polysaccharides, and several three-dimensional structure models of polysaccharide-binding proteins have been reported; and these models provide insights into the mechanisms through which polysaccharides interact with TLR4. In this review, we first discuss the origins of polysaccharides related to TLR4, including polysaccharides from higher plants, fungi, bacteria, algae, and animals. We then briefly describe the glucosidic bond types of TLR4-related heteroglycans and homoglycans and describe the typical molecular weights of TLR4-related polysaccharides. The primary structures and activity relationships of polysaccharides with TLR4/MD-2 are also discussed. Finally, based on the existing interaction models of LPS with TLR4/MD-2 and linear polysaccharides with proteins, we provide insights into the possible interaction models of polysaccharide ligands with TLR4/MD-2. To our knowledge, this review is the first to summarize the primary structures and activity relationships of TLR4-related polysaccharides and the possible mechanisms of interaction for TLR4 and TLR4-related polysaccharides. PMID:27261743

  14. Improved Chemotherapeutic Activity by Morus alba Fruits through Immune Response of Toll-Like Receptor 4

    Bo Yoon Chang

    2015-10-01

    Full Text Available Morus alba L. fruits have long been used in traditional medicine by many cultures. Their medicinal attributes include cardiovascular, hepatoprotective, neuroprotective and immunomodulatory actions. However, their mechanism of macrophage activation and anti-cancer effects remain unclear. The present study investigated the molecular mechanisms of immune stimulation and improved chemotherapeutic effect of M. alba L. fruit extract (MFE. MFE stimulated the production of cytokines, nitric oxide (NO and tumor necrosis factor-α (TNF-α and tumoricidal properties of macrophages. MFE activated macrophages through the mitogen-activated protein kinase (MAPKinase and nuclear factor-κB (NF-κB signaling pathways downstream from toll-like receptor (TLR 4. MFE was shown to exhibit cytotoxicity of CT26 cells via the activated macrophages, even though MFE did not directly affect CT26 cells. In a xenograft mouse model, MFE significantly enhanced anti-cancer activity combined with 5-fluorouracil and markedly promoted splenocyte proliferation, natural killer (NK cell activity, cytotoxic T lymphocyte (CTL activity and IFN-γ production. Immunoglobulin G (IgG antibody levels were significantly increased. These results indicate the indirect anti-cancer activity of MFE through improved immune response mediated by TLR4 signaling. M. alba L. fruit extract might be a potential anti-tumor immunomodulatory candidate chemotherapy agent.

  15. Activation of toll like receptor-3 induces corneal epithelial barrier dysfunction.

    Wei, Jie; Jiang, Hua; Gao, Hongrui; Wang, Guangjie

    2015-06-01

    The epithelial barrier is critical in the maintenance of the homeostasis of the cornea. A number of eye disorders are associated with the corneal epithelial barrier dysfunction. Viral infection is one common eye disease type. This study aims to elucidate the mechanism by which the activation of toll like receptor 3 (TLR3) in the disruption of the corneal epithelial barrier. In this study, HCE cells (a human corneal epithelial cell line) were cultured into epithelial layers using as an in vitro model of the corneal epithelial barrier. PolyI:C was used as a ligand of TLR3. The transepithelial electric resistance (TER) and permeability of the HCE epithelial layer were assessed using as the parameters to evaluate the corneal epithelial barrier integrity. The results showed that exposure to PolyI:C markedly decreased the TER and increased the permeability of the HCE epithelial layers; the levels of cell junction protein, E-cadherin, were repressed by PolyI:C via increasing histone deacetylase-1 (HDAC1), the latter binding to the promoter of E-cadherin and repressed the transcription of E-cadherin. The addition of butyrate (an inhibitor of HDAC1) to the culture blocked the corneal epithelial barrier dysfunction caused by PolyI:C. In conclusion, activation of TLR3 can disrupt the corneal epithelial barrier, which can be blocked by the inhibitor of HDAC1. PMID:25912142

  16. Toll-like receptor 2 activation depends on lipopeptide shedding by bacterial surfactants

    Hanzelmann, Dennis; Joo, Hwang-Soo; Franz-Wachtel, Mirita; Hertlein, Tobias; Stevanovic, Stefan; Macek, Boris; Wolz, Christiane; Götz, Friedrich; Otto, Michael; Kretschmer, Dorothee; Peschel, Andreas

    2016-01-01

    Sepsis caused by Gram-positive bacterial pathogens is a major fatal disease but its molecular basis remains elusive. Toll-like receptor 2 (TLR2) has been implicated in the orchestration of inflammation and sepsis but its role appears to vary for different pathogen species and clones. Accordingly, Staphylococcus aureus clinical isolates differ substantially in their capacity to activate TLR2. Here we show that strong TLR2 stimulation depends on high-level production of phenol-soluble modulin (PSM) peptides in response to the global virulence activator Agr. PSMs are required for mobilizing lipoproteins, the TLR2 agonists, from the staphylococcal cytoplasmic membrane. Notably, the course of sepsis caused by PSM-deficient S. aureus is similar in wild-type and TLR2-deficient mice, but TLR2 is required for protection of mice against PSM-producing S. aureus. Thus, a crucial role of TLR2 depends on agonist release by bacterial surfactants. Modulation of this process may lead to new therapeutic strategies against Gram-positive infections. PMID:27470911

  17. Rice Bran Feruloylated Oligosaccharides Activate Dendritic Cells via Toll-Like Receptor 2 and 4 Signaling

    Chi Chen Lin

    2014-04-01

    Full Text Available This work presents the effects of feruloylated oligosaccharides (FOs of rice bran on murine bone marrow-derived dendritic cells (BMDCs and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4 or TLR-2 but not DCs from mice with mutated TLR4 or TLR2. The mechanism of action of FOs may be mediated by increased phosphorylation of ERK, p38 and JNK mitogen-activated protein kinase (MAPKs and increased NF-kB activity, which are important signaling molecules downstream of TLR-4 and TLR-2. These data suggest that FOs induce DCs maturation through TLR-4 and/or TLR-2 and that FOs might have potential efficacy against tumor or virus infection or represent a candidate-adjuvant approach for application in immunotherapy and vaccination.

  18. Rice bran feruloylated oligosaccharides activate dendritic cells via Toll-like receptor 2 and 4 signaling.

    Lin, Chi Chen; Chen, Hua Han; Chen, Yu Kuo; Chang, Hung Chia; Lin, Ping Yi; Pan, I-Hong; Chen, Der-Yuan; Chen, Chuan Mu; Lin, Su Yi

    2014-01-01

    This work presents the effects of feruloylated oligosaccharides (FOs) of rice bran on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4) or TLR-2 but not DCs from mice with mutated TLR4 or TLR2. The mechanism of action of FOs may be mediated by increased phosphorylation of ERK, p38 and JNK mitogen-activated protein kinase (MAPKs) and increased NF-kB activity, which are important signaling molecules downstream of TLR-4 and TLR-2. These data suggest that FOs induce DCs maturation through TLR-4 and/or TLR-2 and that FOs might have potential efficacy against tumor or virus infection or represent a candidate-adjuvant approach for application in immunotherapy and vaccination. PMID:24762969

  19. Hypothermia Reduces Toll-Like Receptor 3-Activated Microglial Interferon-β and Nitric Oxide Production

    Tomohiro Matsui

    2013-01-01

    Full Text Available Therapeutic hypothermia protects neurons after injury to the central nervous system (CNS. Microglia express toll-like receptors (TLRs that play significant roles in the pathogenesis of sterile CNS injury. To elucidate the possible mechanisms involved in the neuroprotective effect of therapeutic hypothermia, we examined the effects of hypothermic culture on TLR3-activated microglial release of interferon (IFN-β and nitric oxide (NO, which are known to be associated with neuronal cell death. When rat or mouse microglia were cultured under conditions of hypothermia (33°C and normothermia (37°C with a TLR3 agonist, polyinosinic-polycytidylic acid, the production of IFN-β and NO in TLR3-activated microglia at 48 h was decreased by hypothermia compared with that by normothermia. In addition, exposure to recombinant IFN-β and sodium nitroprusside, an NO donor, caused death of rat neuronal pheochromocytoma PC12 cells in a concentration-dependent manner after 24 h. Taken together, these results suggest that the attenuation of microglial production of IFN-β and NO by therapeutic hypothermia leads to the inhibition of neuronal cell death.

  20. Trichomonas vaginalis infection activates cells through toll-like receptor 4.

    Zariffard, M Reza; Harwani, Sailesh; Novak, Richard M; Graham, Parrie J; Ji, Xin; Spear, Gregory T

    2004-04-01

    While Trichomonas vaginalis infection can cause inflammation and influx of leukocytes into the female genital tract, the molecular pathways important in inducing these effects are not known. This study determined if infection with T. vaginalis activates cells through toll-like receptor 4 (TLR4). Genital tract secretions from infected women stimulated TNF-alpha production by cells with functional TLR4 (350 pg/ml) but significantly less by cells that are unresponsive to TLR4 ligands (44 pg/ml, P = 0.001). Secretions collected after clearance of infection also induced significantly lower responses by cells with functional TLR4 (136 pg/ml, P = 0.008). TNF-alpha responses were not reduced by Polymyxin B and did not correlate with beta(2)-defensin levels, indicating that stimulation of cells was not through lipopolysaccharide or beta(2)-defensin. These studies show that T. vaginalis infection results in the appearance in the genital tract of substance(s) that stimulate cells through TLR4, suggesting a mechanism for the inflammation caused by this infection. PMID:15093558

  1. Toll-like receptor activation by helminths or helminth products to alleviate inflammatory bowel disease

    Song YanXia

    2011-09-01

    Full Text Available Abstract Helminth infection may modulate the expression of Toll like receptors (TLR in dendritic cells (DCs and modify the responsiveness of DCs to TLR ligands. This may regulate aberrant intestinal inflammation in humans with helminthes and may thus help alleviate inflammation associated with human inflammatory bowel disease (IBD. Epidemiological and experimental data provide further evidence that reducing helminth infections increases the incidence rate of such autoimmune diseases. Fine control of inflammation in the TLR pathway is highly desirable for effective host defense. Thus, the use of antagonists of TLR-signaling and agonists of their negative regulators from helminths or helminth products should be considered for the treatment of IBD.

  2. Rice Bran Feruloylated Oligosaccharides Activate Dendritic Cells via Toll-Like Receptor 2 and 4 Signaling

    Chi Chen Lin; Hua Han Chen; Yu Kuo Chen; Hung Chia Chang; Ping Yi Lin; I-Hong Pan; Der-Yuan Chen; Chuan Mu Chen; Su Yi Lin

    2014-01-01

    This work presents the effects of feruloylated oligosaccharides (FOs) of rice bran on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4) or TLR-2 but not DCs from mice with ...

  3. Titanium particles activate Toll-like Receptor 4 independently of lipid rafts in RAW264.7 murine macrophages

    Islam, Andrew S.; Beidelschies, Michelle A.; Huml, Anne; Greenfield, Edward M.

    2010-01-01

    Adherent PAMPs (pathogen-associated molecular patterns) act through Toll-like receptor2 (TLR2) and TLR4 to increase the biological activity of orthopaedic wear particles in cell culture and animal models of implant loosening. This study tested whether this is dependent on TLR association with lipid rafts as reported for the response to soluble TLR ligands. For this purpose, RAW264.7 murine macrophages were activated by exposure to titanium particles with adherent PAMPs, soluble lipopolysaccha...

  4. Leishmania lipophosphoglycan (LPG) activates NK cells through toll-like receptor-2.

    Becker, Ingeborg; Salaiza, Norma; Aguirre, Magdalena; Delgado, José; Carrillo-Carrasco, Nuria; Kobeh, Laila Gutiérrez; Ruiz, Adriana; Cervantes, Rocely; Torres, Armando Pérez; Cabrera, Nallely; González, Augusto; Maldonado, Carmen; Isibasi, Armando

    2003-08-31

    Toll-like receptors (TLRs) mediate the cellular response to conserved molecular patterns shared by microorganisms. We report that TLR-2 on human NK cells is upregulated and stimulated by Leishmania major lipophosphoglycan (LPG), a phosphoglycan belonging to a family of unique Leishmania glycoconjugates. We found that purified L. major LPG upregulates both mRNA and the membrane expression of TLR-2 in NK cells. Additionally, IFN-gamma and TNF-alpha production and nuclear translocation of NF-kappaB was enhanced. The activation effect was more intense with LPG purified from infectious metacyclic parasites than from noninfectious procyclic Leishmania. Since the difference between the molecules derived from these two stages of the parasite growth cycle lies exclusively in the number of phosphosaccharide repeat domains and in the composition of glycan side chains that branch off these domains, we propose that TLR-2 possibly distinguishes between phosphorylated glycan repeats on LPG molecules. The effect of LPG on cytokine production and on membrane expression of TLR-2 could be blocked with F(ab')2 fragments of the mAb against LPG (WIC 79.3). Confocal microscopy demonstrated the co-localization of LPG and TLR-2 on the NK cell membrane. Binding of LPG to TLR-2 in NK cells was demonstrated by immunoprecipitations done with anti-TLR-2 and anti-LPG mAb followed by immunoblotting with anti-LPG and anti-TLR-2, respectively. Both antibodies recognized the immune complexes. These results suggest that NK cells are capable of recognition of, and activation by, Leishmania LPG through TLR-2, enabling them to participate autonomously in the innate immune system and thereby increasing the effective destruction of the parasite. PMID:12946842

  5. Counteracting Interactions between Lipopolysaccharide Molecules with Differential Activation of Toll-Like Receptors

    Hajishengallis, George; Martin, Michael; Schifferle, Robert E.; Genco, Robert J.

    2002-01-01

    We investigated counteracting interactions between the lipopolysaccharides (LPS) from Escherichia coli (Ec-LPS) and Porphyromonas gingivalis (Pg-LPS), which induce cellular activation through Toll-like receptor 4 (TLR4) and TLR2, respectively. We found that Ec-LPS induced tolerance in THP-1 cells to subsequent tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) induction by Pg-LPS, though the reverse was not true, and looked for explanatory differential effects on the signal transduction pathway. Cells exposed to Pg-LPS, but not to Ec-LPS, displayed persisting expression of IL-1 receptor-associated kinase without apparent degradation, presumably allowing prolonged relay of downstream signals. Accordingly, cells pretreated with Pg-LPS, but not with Ec-LPS, were effectively activated in response to subsequent exposure to either LPS molecule, as evidenced by assessing nuclear factor (NF)-κB activity. In fact, Pg-LPS primed THP-1 cells for enhanced NF-κB activation and TNF-α release upon restimulation with the same LPS. This was a dose-dependent effect and correlated with upregulation of surface TLR2 expression. Furthermore, we observed inhibition of NF-κB-dependent transcription in a reporter cell line pretreated with Ec-LPS and restimulated with Pg-LPS (compared to cells pretreated with medium only and restimulated with Pg-LPS), but not when the reverse treatment was made. Although Pg-LPS could not make cells tolerant to subsequent activation by Ec-LPS, Pg-LPS inhibited Ec-LPS-induced TNF-α and IL-6 release when the two molecules were added simultaneously into THP-1 cell cultures. Pg-LPS also suppressed P. gingivalis FimA protein-induced NF-κB-dependent transcription in the 3E10/huTLR4 reporter cell line, which does not express TLR2. This rules out competition for common signaling intermediates, suggesting that Pg-LPS may block component(s) of the TLR4 receptor complex. Interactions between TLR2 and TLR4 agonists may be important in the

  6. The biology of Toll-like receptors.

    Means, T K; Golenbock, D T; Fenton, M J

    2000-09-01

    In 1997, a human homologue of the Drosophila Toll protein was described, a protein later to be designated Toll-like receptor 4 (TLR4). Since that time, additional human and murine TLR proteins have been identified. Mammalian TLR proteins appear to represent a conserved family of innate immune recognition receptors. These receptors are coupled to a signaling pathway that is conserved in mammals, insects, and plants, resulting in the activation of genes that mediate innate immune defenses. Numerous studies have now identified a wide variety of chemically-diverse bacterial products that serve as putative ligands for TLR proteins. More recent studies have identified the first endogenous protein ligands for TLR proteins. TLR signaling represents a key feature of innate immune response to pathogen invasion. PMID:10817965

  7. Poke Weed Mitogen Requires Toll-Like Receptor Ligands for Proliferative Activity in Human and Murine B Lymphocytes

    Bekeredjian-Ding, Isabelle; Foermer, Sandra; Kirschning, Carsten J.; Parcina, Marijo; Heeg, Klaus

    2012-01-01

    Poke weed mitogen (PWM), a lectin purified from Phytolacca americana is frequently used as a B cell-specific stimulus to trigger proliferation and immunoglobulin secretion. In the present study we investigated the mechanisms underlying the B cell stimulatory capacity of PWM. Strikingly, we observed that highly purified PWM preparations failed to induce B cell proliferation. By contrast, commercially available PWM preparations with B cell activity contained Toll-like receptor (TLR) ligands suc...

  8. DMPD: Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17502339 Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways ...May 14. (.png) (.svg) (.html) (.csml) Show Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent ...pathways inmacrophage activation. PubmedID 17502339 Title Crosstalk among Jak-STA...T, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation. Authors Hu X, Chen J, Wang L, Iv... File (.svg) HTML File (.html) CSML File (.csml) Open .csml file with CIOPlayer Open .csml file wit

  9. S6K1 Negatively Regulates TAK1 Activity in the Toll-Like Receptor Signaling Pathway

    Kim, So Yong; Baik, Kyung-Hwa; Baek, Kwan-Hyuck; Chah, Kyong-Hwa; Kim, Kyung Ah; Moon, Gyuyoung; Jung, Eunyu; Kim, Seong-Tae; Shim, Jae-Hyuck; Greenblatt, Matthew B.; Chun, Eunyoung; Lee, Ki-Young

    2014-01-01

    Transforming growth factor β (TGF-β)-activated kinase 1 (TAK1) is a key regulator in the signals transduced by proinflammatory cytokines and Toll-like receptors (TLRs). The regulatory mechanism of TAK1 in response to various tissue types and stimuli remains incompletely understood. Here, we show that ribosomal S6 kinase 1 (S6K1) negatively regulates TLR-mediated signals by inhibiting TAK1 activity. S6K1 overexpression causes a marked reduction in NF-κB and AP-1 activity induced by stimulation...

  10. DMPD: Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15031527 Toll-like receptor 3: a link between toll-like receptor, interferon and viruses... (.csml) Show Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. PubmedID 1503...1527 Title Toll-like receptor 3: a link between toll-like receptor, interferon and viruses

  11. Evidence for Activation of Toll-Like Receptor and Receptor for Advanced Glycation End Products in Preterm Birth

    Taketoshi Noguchi

    2010-01-01

    Full Text Available Objective. Individuals with inflammation have a myriad of pregnancy aberrations including increasing their preterm birth risk. Toll-like receptors (TLRs and receptor for advanced glycation end products (RAGE and their ligands were all found to play a key role in inflammation. In the present study, we reviewed TLR and RAGE expression, their ligands, and signaling in preterm birth. Research Design and Methods. A systematic search was performed in the electronic databases PubMed and ScienceDirect up to July 2010, combining the keywords “preterm birth,” “TLR”, “RAGE”, “danger signal”, “alarmin”, “genomewide,” “microarray,” and “proteomics” with specific expression profiles of genes and proteins. Results. This paper provides data on TLR and RAGE levels and critical downstream signaling events including NF-kappaB-dependent proinflammatory cytokine expression in preterm birth. About half of the genes and proteins specifically present in preterm birth have the properties of endogenous ligands “alarmin” for receptor activation. The interactions between the TLR-mediated acute inflammation and RAGE-mediated chronic inflammation have clear implications for preterm birth via the TLR and RAGE system, which may be acting collectively. Conclusions. TLR and RAGE expression and their ligands, signaling, and functional activation are increased in preterm birth and may contribute to the proinflammatory state.

  12. Toll-like receptors in neurodegeneration

    Owens, Trevor

    2009-01-01

    Innate pattern recognition receptors are implicated in first-line defense against pathogens but also participate in maintenance of tissue homeostasis and response to injury. This chapter reviews the role of Toll-like receptors (TLRs) in neuronal and glial responses that are associated with...... neurodegeneration. Accompanying roles for infection and inflammation, involvement in clinical neurodegenerative disorders, and heterogeneity of glial response are discussed. A "strength of signal" hypothesis is advanced in an attempt to reconcile evolutionarily selected and therefore likely beneficial effects of...... TLR signaling in the nervous system with capability for neurotoxocity and gliotoxicity....

  13. Analysis by Flow Cytometry of B-Cell Activation and Antibody Responses Induced by Toll-Like Receptors.

    Pone, Egest J

    2016-01-01

    Toll-like receptors (TLRs) are expressed in B lymphocytes and contribute to B-cell activation, antibody responses, and their maturation. TLR stimulation of mouse B cells induces class switch DNA recombination (CSR) to isotypes specified by cytokines, and also induces formation of IgM(+) as well as class-switched plasma cells. B-cell receptor (BCR) signaling, while on its own inducing limited B-cell proliferation and no CSR, can enhance CSR driven by TLRs. Particular synergistic or antagonistic interactions among TLR pathways, BCR, and cytokine signaling can have important consequences for B-cell activation, CSR, and plasma cell formation. This chapter outlines protocols for the induction and analysis of B-cell activation and antibody production by TLRs with or without other stimuli. PMID:26803633

  14. Toll-Like Receptors in Angiogenesis

    Karsten Grote

    2011-01-01

    Full Text Available Toll-like receptors (TLRs are known as pattern-recognition receptors related to the Toll protein of Drosophila. After recognition of pathogen-associated molecular patterns of microbial origin, the TLRs alert the immune system, and initiate innate and adaptive immune responses. The TLR system, though, is not confined solely to the leukocyte-mediated immune defense against exogenous pathogens. Besides myeloid cells, TLR expression has been reported in multiple tissues and cell types, including epithelial and endothelial cells. Moreover, despite the microbial patterns that are commonly accepted as TLR ligands, there is increasing evidence that TLRs also recognize host-derived molecules. In this regard, recent studies point to an involvement of TLRs in various chronic inflammatory disorders and cardiovascular diseases, including atherosclerosis, rheumatoid arthritis, systemic lupus erythematosus, and even cancer. A common feature of these disorders is an enhanced so-called inflammation-induced angiogenesis. However, inflammation-induced angiogenesis is not solely a key component of pathogen defense during acute infection or chronic inflammatory disorders, but also plays a critical role in repair mechanisms, e.g., wound healing and subsequent tissue regeneration. Interestingly, the latest research could coincidentally demonstrate that TLR activation promotes angiogenesis in various inflammatory settings in response to both exogenous and endogenous ligands, although the precise mode of action of TLRs in this context still remains ambiguous. The objective of this review is to present evidence for the implication of TLRs in angiogenesis during physiological and pathophysiological processes, and the potential clinical relevance for new treatment regimes involving TLR modulation.

  15. Microglia-Secreted Galectin-3 Acts as a Toll-like Receptor 4 Ligand and Contributes to Microglial Activation

    Miguel Angel Burguillos

    2015-03-01

    Full Text Available Inflammatory response induced by microglia plays a critical role in the demise of neuronal populations in neuroinflammatory diseases. Although the role of toll-like receptor 4 (TLR4 in microglia’s inflammatory response is fully acknowledged, little is known about endogenous ligands that trigger TLR4 activation. Here, we report that galectin-3 (Gal3 released by microglia acts as an endogenous paracrine TLR4 ligand. Gal3-TLR4 interaction was further confirmed in a murine neuroinflammatory model (intranigral lipopolysaccharide [LPS] injection and in human stroke subjects. Depletion of Gal3 exerted neuroprotective and anti-inflammatory effects following global brain ischemia and in the neuroinflammatory LPS model. These results suggest that Gal3-dependent-TLR4 activation could contribute to sustained microglia activation, prolonging the inflammatory response in the brain.

  16. T-cell activation is enhanced by targeting IL-10 cytokine production in toll-like receptor- stimulated macrophages

    Walk RM

    2012-11-01

    Full Text Available Ryan M Walk,1,2 Steven T Elliott,2 Felix C Blanco,2 Jason A Snyder,2 Ashley M Jacobi,3 Scott D Rose,3 Mark A Behlke,3 Aliasger K Salem,4 Stanislav Vukmanovic,2 Anthony D Sandler21Department of Surgery, Walter Reed Army Medical Center, Washington, DC, USA; 2Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, DC, USA; 3Integrated DNA Technologies, Coralville, IA, USA; 4Division of Pharmaceutics, University of Iowa, Iowa City, IA, USAAbstract: Toll-like receptor (TLR agonists represent potentially useful cancer vaccine adjuvants in their ability to stimulate antigen-presenting cells (APCs and subsequently amplify the cytotoxic T-cell response. The purpose of this study was to characterize APC responses to TLR activation and to determine the subsequent effect on lymphocyte activation. We exposed murine primary bone marrow-derived macrophages to increasing concentrations of agonists to TLRs 2, 3, 4, and 9. This resulted in a dose-dependent increase in production of not only tumor necrosis factor–alpha (TNF-α, a surrogate marker of the proinflammatory response, but also interleukin 10 (IL-10, a well-described inhibitory cytokine. Importantly, IL-10 secretion was not induced by low concentrations of TLR agonists that readily produced TNF-α. We subsequently stimulated lymphocytes with anti-CD3 antibody in the presence of media from macrophages activated with higher doses of TLR agonists and observed suppression of interferon gamma release. Use of both IL-10 knockout macrophages and IL-10 small-interfering RNA (siRNA ablated this suppressive effect. Finally, IL-10 siRNA was successfully used to suppress CpG-induced IL-10 production in vivo. We conclude that TLR-mediated APC stimulation can induce a paradoxical inhibitory effect on T-cell activation mediated by IL-10.Keywords: toll-like receptors, innate immunity, IL-10

  17. Glucuronic acid and the ethanol metabolite ethyl-glucuronide cause Toll-like receptor 4 activation and enhanced pain

    Lewis, Susannah S.; Hutchinson, Mark R; Zhang, Yingning; Hund, Dana K.; Maier, Steven F.; Rice, Kenner C.; Watkins, Linda R

    2013-01-01

    We have previously observed that the non-opioid morphine metabolite, morphine-3-glucuronide, enhances pain via a toll-like receptor 4 (TLR4) dependent mechanism. The present studies were undertaken to determine whether TLR4-dependent pain enhancement generalizes to other classes of glucuronide metabolites. In silico modeling predicted that glucuronic acid alone and ethyl glucuronide, a minor but long-lasting ethanol metabolite, would dock to the same MD-2 portion of the TLR4 receptor complex ...

  18. Toll-Like Receptors and Myocardial Inflammation

    Yan Feng

    2011-01-01

    Full Text Available Toll-like receptors (TLRs are a member of the innate immune system. TLRs detect invading pathogens through the pathogen-associated molecular patterns (PAMPs recognition and play an essential role in the host defense. TLRs can also sense a large number of endogenous molecules with the damage-associated molecular patterns (DAMPs that are produced under various injurious conditions. Animal studies of the last decade have demonstrated that TLR signaling contributes to the pathogenesis of the critical cardiac conditions, where myocardial inflammation plays a prominent role, such as ischemic myocardial injury, myocarditis, and septic cardiomyopathy. This paper reviews the animal data on (1 TLRs, TLR ligands, and the signal transduction system and (2 the important role of TLR signaling in these critical cardiac conditions.

  19. Mycoplasma lipoproteins and Toll-like receptors

    Ling-ling ZUO; Yi-mou WU; Xiao-xing YOU

    2009-01-01

    Mycoplasmas, the smallest free-living, self-replicating bacteria with diameters of 200 to 800 nm, have been reported to be associated with human diseases. It is well known that the mycoplasma lipoprotein/peptide is able to modulate the host immune system, whose N-terminal structure is an important factor in inducing immunity and distinguishing Toll-like receptors (TLRs). However, there is still no clear elucidation about the pathogenic mechanism of mycoplasma lipoprotein/peptide and the signaling pathway. Some researchers have focused on understanding the structures of these proteins and the relationships between their structure and biological function. This review provides an update on the research in this field.

  20. Immune activation by medium-chain triglyceride-containing lipid emulsions is not modulated by n-3 lipids or toll-like receptor 4

    Olthof, E.D.; Gulich, A.F.; Renne, M.F.; Landman, S.; Joosten, L.A.B.; Roelofs, H.M.; Wanten, G.J.A.

    2015-01-01

    BACKGROUND: Saturated medium-chain triglycerides (MCT) as part of the parenteral lipid regimen (50% MCT and 50% long chain triglycerides (LCT)) activate the immune system in vitro. Fish oil (FO)-derived n-3 fatty acids (FA) inhibit saturated FA-induced immune activation via a toll-like receptor (TLR

  1. Toll-like receptor 4 is required for α-synuclein dependent activation of microglia and astroglia

    Fellner, Lisa; Irschick, Regina; Schanda, Kathrin; Reindl, Markus; Klimaschewski, Lars; Poewe, Werner; Wenning, Gregor K; Stefanova, Nadia

    2013-01-01

    Alpha-synucleinopathies (ASP) are neurodegenerative disorders, characterized by accumulation of misfolded α-synuclein, selective neuronal loss, and extensive gliosis. It is accepted that microgliosis and astrogliosis contribute to the disease progression in ASP. Toll-like receptors (TLRs) are expressed on cells of the innate immune system, including glia, and TLR4 dysregulation may play a role in ASP pathogenesis. In this study we aimed to define the involvement of TLR4 in microglial and astr...

  2. Fibrinogen, an endogenous ligand of Toll-like receptor 4, activates monocytes in pre-eclamptic patients.

    Al-ofi, Ebtisam; Coffelt, Seth B; Anumba, Dilly O

    2014-06-01

    Pre-eclampsia (PE) remains the leading cause of pregnancy-associated mortality and morbidity, urging the need for a better understanding of its aetiology and pathophysiological progression. A key characteristic of PE is a systemic, exaggerated, inflammatory condition involving abnormal cytokine levels in serum, altered immune cell phenotype and Th1/Th2-type immunological imbalance. However, it is unknown how this heightened inflammatory condition manifests. We previously reported increased expression of the lipopolysaccharide receptor, Toll-like receptor 4 (TLR4), on monocytes from PE patients compared with normotensive, pregnant patients (NP). This upregulation of TLR4 on PE monocytes was accompanied by a hyper-responsiveness to bacterial TLR4 ligands. To determine whether non-microbial, endogenous TLR4 ligands also activate monocytes from PE patients, we investigated the expression of host-derived TLR4 ligands and the response of monocytes to these endogenous ligands. Plasma levels of fibrinogen - but not fibronectin or heparan sulphate - were higher in PE patients than in NP. Exposure to fibrinogen was associated with significantly increased production of inflammatory cytokines by monocytes from PE patients. Interestingly, this effect was not observed with NP monocytes. Our findings suggest that the fibrinogen-TLR4 axis might play an important role in the atypical activation of monocytes observed in PE patients that may contribute to the exaggerated inflammatory condition. PMID:24661950

  3. Role of Toll-like receptor 4 in inflammatory reactions of hippocampal neurons

    Yae Hu; Jiahui Mao; Yu Zhang; Ailing Zhou

    2013-01-01

    Lipopolysaccharide stimulates Toll-like receptor 4 on immune cells to produce immune mediators. Toll-like receptor 4 is also expressed by non-immune cells, which can be stimulated by lipopolysaccharide. However, whether Toll-like receptor 4 is expressed by primary cultured hippocampal neurons and its specific role in lipopolysaccharide-induced neuroinflammation is currently undefined. In this study, Toll-like receptor 4 antibody blocking was used to analyze the Toll-like receptor 4 signaling pathway and changes in inflammation of lipopolysaccharide stimulated hippocampal neurons. Immunofluorescence showed that Toll-like receptor 4 protein was mainly located in the membrane of hippocampal neurons. Quantitative reverse transcription-PCR and western blot assay showed that after stimulation of lipopolysaccharide, the mRNA and protein levels of Toll-like receptor 4 and the mRNA levels of interleukin-1β and tumor necrosis factor-α were significantly increased. In addition, there was increased phosphorylation and degradation of kappa B α inhibitor in the cytosol and increased nuclear factor-κB p65 expression in the nuclei. Pretreatment with Toll-like receptor 4 antibody could almost completely block this increase. These experimental findings indicate that lipopolysaccharide participates in neuroinflammation by stimulating Toll-like receptor 4/nuclear factor-κB pathway in hippocampal neurons, which may be both "passive victims" and "activators" of neuroinflammation.

  4. Toll-like receptor activation enhances cell-mediated immunity induced by an antibody vaccine targeting human dendritic cells

    Berger Marc A

    2007-01-01

    Full Text Available Abstract Previously, we have successfully targeted the mannose receptor (MR expressed on monocyte-derived dendritic cells (DCs using a fully human MR-specific antibody, B11, as a vehicle to deliver whole protein tumor antigens such as the human chorionic gonadotropin hormone (hCGβ. Since MRs play a role in bridging innate immunity with adaptive immunity we have explored several toll-like receptor (TLR-specific ligands that may synergize with MR targeting and be applicable as adjuvants in the clinic. We demonstrate that antigen-specific helper and cytolytic T cells from both healthy donors and cancer patients were effectively primed with B11-hCGβ-treated autologous DCs when a combination of one or several TLR ligands is used. Specifically, concomitant signaling of DCs via TLR3 with dsRNA (poly I:C and DC TLR 7/8 with Resiquimod (R-848, respectively, elicited efficient antigen presentation-mediated by MR-targeting. We demonstrate that MR and TLRs contribute towards maturation and activation of DCs by a mechanism that may be driven by a combination of adjuvant and antibody vaccines that specifically deliver antigenic targets to DCs.

  5. Hyper-responsive Toll-like receptor 7 and 9 activation in NADPH oxidase-deficient B lymphoblasts.

    McLetchie, Shawna; Volpp, Bryan D; Dinauer, Mary C; Blum, Janice S

    2015-12-01

    Chronic granulomatous disease (CGD) is an inherited immunodeficiency linked with mutations in the multi-subunit leucocyte NADPH oxidase. Myeloid-derived phagocytic cells deficient in NADPH oxidase fail to produce sufficient levels of reactive oxygen species to clear engulfed pathogens. In this study we show that oxidase also influences B-cell functions, including responses to single-stranded RNA or unmethylated DNA by endosomal Toll-like receptors (TLRs) 7 and 9. In response to TLR7/9 ligands, B-cell lines derived from patients with CGD with mutations in either the NADPH oxidase p40(phox) or p47(phox) subunits produced only low levels of reactive oxygen species. Remarkably, cytokine secretion and p38 mitogen-activated protein kinase activation by these oxidase-deficient B cells was significantly increased upon TLR7/9 activation when compared with oxidase-sufficient B cells. Increased TLR responsiveness was also detected in B cells from oxidase-deficient mice. NADPH oxidase-deficient patient-derived B cells also expressed enhanced levels of TLR7 and TLR9 mRNA and protein compared with the same cells reconstituted to restore oxidase activity. These data demonstrate that the loss of oxidase function associated with CGD can significantly impact B-cell TLR signalling in response to nucleic acids with potential repercussions for auto-reactivity in patients. PMID:26340429

  6. MR imaging and T2 measurements in peripheral nerve repair with activation of Toll-like receptor 4 of neurotmesis

    To investigate the role of MR imaging in neurotmesis combined with surgical repair and Toll-like receptor 4 (TLR4) activation. Forty-eight rats received subepineurial microinjection of the TLR4 agonist lipopolysaccharide (LPS, n = 24) or phosphate buffered saline (PBS, n = 24) immediately after surgical repair of the transected sciatic nerve. Sequential fat-suppressed T2-weighted imaging and quantitative T2 measurements were obtained at 3, 7, 14 and 21 days after surgery, with histologic assessments performed at regular intervals. T2 relaxation times and histological quantification of the distal stumps were measured and compared. The distal stumps of transected nerves treated with LPS or PBS both showed persistent enlargement and hyperintense signal. T2 values of the distal stumps showed a rapid rise to peak level followed by a rapid decline pattern in nerves treated with LPS, while exhibiting a slow rise to peak value followed by a slow decline in nerves treated with PBS. Nerves treated with LPS exhibited more prominent macrophage recruitment, faster myelin debris clearance and more pronounced nerve regeneration. Nerves treated with TLR4 activation had a characteristic pattern of T2 value change over time. Longitudinal T2 measurements can be used to detect the enhanced repair effect associated with TLR4 activation in the surgical repair of neurotmesis. (orig.)

  7. MR imaging and T2 measurements in peripheral nerve repair with activation of Toll-like receptor 4 of neurotmesis

    Zhang, Xiang; Zhang, Fang; Lu, Liejing; Li, Haojiang; Wen, Xuehua; Shen, Jun [Sun Yat-Sen University, Department of Radiology, Sun Yat-Sen Memorial Hospital, Guangzhou, Guangdong (China)

    2014-05-15

    To investigate the role of MR imaging in neurotmesis combined with surgical repair and Toll-like receptor 4 (TLR4) activation. Forty-eight rats received subepineurial microinjection of the TLR4 agonist lipopolysaccharide (LPS, n = 24) or phosphate buffered saline (PBS, n = 24) immediately after surgical repair of the transected sciatic nerve. Sequential fat-suppressed T2-weighted imaging and quantitative T2 measurements were obtained at 3, 7, 14 and 21 days after surgery, with histologic assessments performed at regular intervals. T2 relaxation times and histological quantification of the distal stumps were measured and compared. The distal stumps of transected nerves treated with LPS or PBS both showed persistent enlargement and hyperintense signal. T2 values of the distal stumps showed a rapid rise to peak level followed by a rapid decline pattern in nerves treated with LPS, while exhibiting a slow rise to peak value followed by a slow decline in nerves treated with PBS. Nerves treated with LPS exhibited more prominent macrophage recruitment, faster myelin debris clearance and more pronounced nerve regeneration. Nerves treated with TLR4 activation had a characteristic pattern of T2 value change over time. Longitudinal T2 measurements can be used to detect the enhanced repair effect associated with TLR4 activation in the surgical repair of neurotmesis. (orig.)

  8. Microbial Hijacking of Complement–Toll-like Receptor Crosstalk*

    WANG Min; Krauss, Jennifer L.; Domon, Hisanori; Hosur, Kavita B.; Liang, Shuang; Magotti, Paola; Triantafilou, Martha; Triantafilou, Kathy; Lambris, John D.; Hajishengallis, George

    2010-01-01

    Recent evidence suggests that complement and Toll-like receptors (TLRs) crosstalk to coordinate innate immunity. We report a novel immune subversion mechanism involving microbial exploitation of the ability of complement and TLRs for communication. Porphyromonas gingivalis, a major oral and systemic pathogen expressing complement C5 convertase-like activity, was shown to synergize with C5a for cAMP elevation resulting in macrophage immunosuppression and enhanced pathogen survival in vitro and...

  9. Lubricin/Proteoglycan 4 binds to and regulates the activity of Toll-Like Receptors In Vitro.

    Iqbal, S M; Leonard, C; Regmi, S C; De Rantere, D; Tailor, P; Ren, G; Ishida, H; Hsu, Cy; Abubacker, S; Pang, D Sj; Salo, P T; Vogel, H J; Hart, D A; Waterhouse, C C; Jay, G D; Schmidt, T A; Krawetz, R J

    2016-01-01

    Proteoglycan 4 (PRG4/lubricin) is secreted by cells that reside in articular cartilage and line the synovial joint. Lubricin may play a role in modulating inflammatory responses through interaction with CD44. This led us to examine if lubricin could be playing a larger role in the modulation of inflammation/immunity through interaction with Toll-like receptors (TLRs). Human Embryonic Kidney (HEK) cells overexpressing TLRs 2, 4 or 5 and surface plasmon resonance were employed to determine if full length recombinant human lubricin was able to bind to and activate TLRs. Primary human synovial fibroblasts were also examined using flow cytometry and Luminex multiplex ELISA. A rat destabilization model of osteoarthritis (OA) was used to determine if lubricin injections were able to regulate pain and/or inflammation in vivo. Lubricin can bind to and regulate the activity of TLRs, leading to downstream changes in inflammatory signalling independent of HA. We confirmed these findings in vivo through intra-articular injections of lubricin in a rat OA model where the inhibition of systemic inflammatory signaling and reduction in pain were observed. Lubricin plays an important role in regulating the inflammatory environment under both homeostatic and tissue injury states. PMID:26752378

  10. Toll-like receptors of deuterostome invertebrates

    Honoo eSatake

    2012-02-01

    Full Text Available Defensive systems against pathogens are responsible not only for survival or lifetime of an individual but also for the evolution of a species. Innate immunity is expected to be more important for invertebrates than mammals, given that adaptive immunity has not been acquired in the former. Toll-like receptors (TLRs have been shown to play a crucial role in host defense of pathogenic microbes in innate immunity of mammals. Recent genome-wide analyses have suggested that TLR or their related genes are conserved in invertebrates. In particular, numerous TLR-related gene candidates were detected in deuterostome invertebrates including a sea urchin (222 TLR-related gene candidates and amphioxus (72 TLR-related gene candidates. Molecular phylogenetic analysis verified that most of sea urchin or amphioxus TLR candidates are paralogous, suggesting that these organisms expanded TLR-related genes in a species-specific manner. In contrast, another deuterostome invertebrate, an ascidian, Ciona intestinalis, was found to possess only two TLR genes. Moreover, Ciona TLRs, Ci-TLR1 and -2, were shown to possess hybrid functionality of mammalian TLRs. Such functionality of Ci-TLRs could not be predicted by sequence comparison with vertebrate TLRs, indicating the confounding evolutionary lineages of deuterostome invertebrate TLRs or their candidates. In this review article, we present recent advances in studies of TLRs or their candidates of deuterostome invertebrates, and provide insight into an evolutionary process of TLRs.

  11. Toll-like receptor 2 or toll-like receptor 4 deficiency does not modify lupus in MRLlpr mice.

    Simon J Freeley

    Full Text Available Systemic lupus erythematosus is an autoimmune disease with a high morbidity and nephritis is a common manifestation. Previous studies in murine lupus models have suggest a role for Toll-like receptor 2 and 4. We examined the role of these molecules in MRL lpr mice which is one of the most established and robust murine models. We compared disease parameters in Toll-like receptor 2 or Toll-like receptor 4 deficient mice with their littermate controls. We found no difference in the severity of glomerulonephritis as assessed by histology, serum creatinine and albuminuria when Toll-like receptor 2 or Toll-like receptor 4 deficient MRLlpr mice were compared with Toll-like receptor sufficient controls. We also found similar levels of anti-dsDNA and anti-ssDNA antibodies. These results show that Toll-like receptor 2 and Toll-like receptor 4 do not play a significant role in MRLlpr mice, and therefore they may not be important in human lupus.

  12. Prenatal activation of toll-like receptor-4 dampens adult hippocampal neurogenesis in an IL-6 dependent manner

    Abdeslam eMouihate

    2016-06-01

    Full Text Available Prenatal immune challenge has been associated with alteration in brain development and plasticity that last into adulthood. We have previously shown that prenatal activation of toll-like receptor 4 by LPS induces IL-6-dependent STAT-3 signaling pathway in the fetal brain. Whether this IL-6-dependent activation of fetal brain results in long lasting impact in brain plasticity is still unknown. Furthermore, it has been shown that prenatal LPS heightens the hypothalamic-pituitary-adrenal (HPA response in adulthood. In the present study we tested whether LPS administration during pregnancy affects neurogenesis in adult male offspring. Because corticosterone, the end-product of HPA axis activity in rats, alters neurogenesis we tested whether this enhanced HPA axis responsiveness in adult male offspring played a role in the long lasting impact of LPS on neurogenesis during adulthood. Pregnant rats were given either LPS, or LPS and an IL-6 neutralizing antibody (IL-6Ab. The newly born neurons were monitored in the subventricular zone (SVZ and the dentate gyrus (DG of the hippocampus of adult male offspring by monitoring doublecortin and T-box brain protein 2 expression: two well-established markers of newly born neurons. Prenatal LPS decreased the number of newly born neurons in the DG, but not in the SVZ of adult offspring. This decreased number of newly born neurons in the DG was absent when IL-6Ab was co-injected with LPS during pregnancy. Furthermore, administration of a corticosterone receptor blocker, RU-486, to adult offspring blunted the prenatal LPS induced decrease in newly born neurons in the DG.These data suggest that maternally triggered IL-6 plays a crucial role in the long lasting impact of LPS on adult neurogenesis.

  13. Toll-like receptor expression and activation in astroglia: differential regulation by HIV-1 Tat, gp120, and morphine

    El-Hage, Nazira; PODHAIZER, Elizabeth M.; Sturgill, Jamie; Hauser, Kurt F.

    2011-01-01

    In this study we determine whether morphine alone or in combination with HIV-1 Tat or gp120 affects the expression of Toll-like receptors (TLRs) by astrocytes and to assess whether TLRs expressed by astrocytes function in the release of inflammatory mediators in vitro. TLR profiling by immunofluorescence microscopy, flow cytometry, in-cell westerns, and RT-PCR showed that subpopulations of astrocytes possessed TLR 2, TLR3, TLR4, and TLR9 antigenicity. Exposure to HIV-1 Tat, gp120, and/or morp...

  14. Differential cell reaction upon Toll-like receptor 4 and 9 activation in human alveolar and lung interstitial macrophages

    Meyerhans Andreas

    2010-09-01

    Full Text Available Abstract Background Investigations on pulmonary macrophages (MΦ mostly focus on alveolar MΦ (AM as a well-defined cell population. Characteristics of MΦ in the interstitium, referred to as lung interstitial MΦ (IM, are rather ill-defined. In this study we therefore aimed to elucidate differences between AM and IM obtained from human lung tissue. Methods Human AM and IM were isolated from human non-tumor lung tissue from patients undergoing lung resection. Cell morphology was visualized using either light, electron or confocal microscopy. Phagocytic activity was analyzed by flow cytometry as well as confocal microscopy. Surface marker expression was measured by flow cytometry. Toll-like receptor (TLR expression patterns as well as cytokine expression upon TLR4 or TLR9 stimulation were assessed by real time RT-PCR and cytokine protein production was measured using a fluorescent bead-based immunoassay. Results IM were found to be smaller and morphologically more heterogeneous than AM, whereas phagocytic activity was similar in both cell types. HLA-DR expression was markedly higher in IM compared to AM. Although analysis of TLR expression profiles revealed no differences between the two cell populations, AM and IM clearly varied in cell reaction upon activation. Both MΦ populations were markedly activated by LPS as well as DNA isolated from attenuated mycobacterial strains (M. bovis H37Ra and BCG. Whereas AM expressed higher amounts of inflammatory cytokines upon activation, IM were more efficient in producing immunoregulatory cytokines, such as IL10, IL1ra, and IL6. Conclusion AM appear to be more effective as a non-specific first line of defence against inhaled pathogens, whereas IM show a more pronounced regulatory function. These dissimilarities should be taken into consideration in future studies on the role of human lung MΦ in the inflammatory response.

  15. Lactobacilli inhibit interleukin-8 production induced by Helicobacter pylori lipopolysaccharide-activated Toll-like receptor 4

    Chao Zhou; Feng-Zhen Ma; Xue-Jie Deng; Hong Yuan; Hong-Sheng Ma

    2008-01-01

    AIM: To investigate the effect of Lactobacillus bulgaricus (LBG) on the Toll-like receptor 4 (TLR4) pathway and interleukin-8 (IL-8) production in SGC-7901 cells treated with Helicobacter pyloriSydney strain 1 lipopolysaccharide (H pyloriSS1-LPS).METHODS: SGC-7901 cells were treated with H pyIoriSS1-LPS in the presence or absence of pretreatment for 1 h with viable LBG or supematant recovered from LBG culture MRS broth (LBG-s). Cellular lysates were prepared for Western blot with anti-TLR4,anti-transforming growth factor β-activated kinase 1 (TAK1), anti-phospho-TAK1, anti-nuclear factor κB (NF-κB), anti-p38 mitogen-activated protein kinase (p38MAPK), and anti-phospho-p38MAPK antibodies.The amount of IL-8 in cell culture medium was measured by ELISA.RESULTS: H pyloriSS1-LPS up-regulated the expression of TLR4, stimulated the phosphorylation of TAK1, subsequently enhanced the activation of NFκB and the phosphorylation of p38MAPK in a timedependent manner, leading to augmentation of IL-8 production in SGC-7901 cells. Viable LBG or LBG-s pretreatment attenuated the expression of TLR4,inhibited the phosphorylation of TAK1 and p38MAPK,prevented the activation of NF-κB, and consequently blocked IL-8 production.CONCLUSION: H pyloriSS1-LPS induces IL-8production through activating TLR4 signaling in SGC-7901 cells and viable LBG or LBG-s prevents H pyloriSS1-LPS-mediated IL-8 production via inhibition of the TLR4 pathway.

  16. Improved Chemotherapeutic Activity by Morus alba Fruits through Immune Response of Toll-Like Receptor 4

    Bo Yoon Chang; Seon Beom Kim; Mi Kyeong Lee; Hyun Park; Sung Yeon Kim

    2015-01-01

    Morus alba L. fruits have long been used in traditional medicine by many cultures. Their medicinal attributes include cardiovascular, hepatoprotective, neuroprotective and immunomodulatory actions. However, their mechanism of macrophage activation and anti-cancer effects remain unclear. The present study investigated the molecular mechanisms of immune stimulation and improved chemotherapeutic effect of M. alba L. fruit extract (MFE). MFE stimulated the production of cytokines, nitric oxide (...

  17. Src Kinases Are Required for a Balanced Production of IL-12/IL-23 in Human Dendritic Cells Activated by Toll-Like Receptor Agonists

    Kuka, Mirela; Baronio, Roberta; Valentini, Sara; Monaci, Elisabetta; Muzzi, Alessandro; Aprea, Susanna; De Gregorio, Ennio; D'Oro, Ugo

    2010-01-01

    Background Pathogen recognition by dendritic cells (DC) is crucial for the initiation of both innate and adaptive immune responses. Activation of Toll-like Receptors (TLRs) by microbial molecular patterns leads to the maturation of DC, which present the antigen and activate T cells in secondary lymphoid tissues. Cytokine production by DC is critical for shaping the adaptive immune response by regulating T helper cell differentiation. It was previously shown by our group that Src kinases play ...

  18. Toll-like receptor 4 mediates microglial activation and production of inflammatory mediators in neonatal rat brain following hypoxia: role of TLR4 in hypoxic microglia

    Yao Linli; Kan Enci Mary; Lu Jia; Hao Aijun; Dheen S Thameem; Kaur Charanjit; Ling Eng-Ang

    2013-01-01

    Abstract Background Hypoxia induces microglial activation which causes damage to the developing brain. Microglia derived inflammatory mediators may contribute to this process. Toll-like receptor 4 (TLR4) has been reported to induce microglial activation and cytokines production in brain injuries; however, its role in hypoxic injury remains uncertain. We investigate here TLR4 expression and its roles in neuroinflammation in neonatal rats following hypoxic injury. Methods One day old Wistar rat...

  19. Toll-like receptors:function and roles in asthma

    周林福; 殷凯生

    2004-01-01

    @@ Asthma is a chronic airway inflammatory disease involved with multiple susceptible genes for atopy. Toll-like receptors (TLRs), an ancient though newly characterized and evolutionarily conserved immune receptor family, activate the mononuclear phagocyte system via both myeloid differentiation marker 88 (MyD88)-dependent and -independent signaling pathways. TLRs might play a key role in asthma by recognition of pathogenic microorganisms, activation of innate immunity, regulation of adaptive immunity, and induction of immune tolerance. For future immunotherapy of asthma, it is promising to develop novel immune regulators by selectively targeting blockade of TLRs.

  20. CCL-34, a synthetic toll-like receptor 4 activator, modulates differentiation and maturation of myeloid dendritic cells.

    Fu, Shu-Ling; Lin, Chun-Cheng; Hsu, Ming-Ling; Liu, Sheng-Hung; Huang, Yu-Chuen; Chen, Yu-Jen

    2016-03-01

    CCL-34, a synthetic α-galactosylceramide analog, has been reported as an activator of toll-like receptor 4 (TLR4) in macrophages. TLR4 is highly expressed in dendritic cell (DC) and several TLR4 agonists are known to trigger DC maturation. We herein evaluated the effect of CCL-34 on DC maturation. Human CD14+ monocyte-derived immature DC were treated with CCL-34, its inactive structural analog CCL-44, or LPS to assess the DC maturation. CCL-34 induced DC maturation according to their characteristically dendrite-forming morphology, CD83 expression and IL-12p70 production. The allostimulatory activity of DC on proliferation of naive CD4+CD45+RA+ T cells and their secretion of interferon-γ was increased by CCL-34. Phagocytosis, an important function of immature DC, was reduced after CCL-34 treatment. All these effects related to DC maturation were evidently induced by positive control LPS but not by CCL-44 treatment. TLR4 neutralization impaired human DC maturation triggered by CCL-34. The induction of IL-12, a hallmark of DC maturation, by CCL-34 and LPS was only evident in TLR4-competent C3H/HeN, but not in TLR4-defective C3H/HeJ mice. CCL-34 could further elicit the antigen presentation capability in mice inoculated with doxorubicin-treated colorectal cancer cells. In summary, CCL-34 triggers DC maturation via a TLR4-dependent manner, which supports its potential application as an immunostimulator. PMID:26883191

  1. Toll-like receptor 4 contributes to chronic itch, alloknesis, and spinal astrocyte activation in male mice.

    Liu, Tong; Han, Qingjian; Chen, Gang; Huang, Ya; Zhao, Lin-Xia; Berta, Temugin; Gao, Yong-Jing; Ji, Ru-Rong

    2016-04-01

    Increasing evidence suggests that Toll-like receptor 4 (TLR4) contributes importantly to spinal cord glial activation and chronic pain sensitization; however, its unique role in acute and chronic itch is unclear. In this study, we investigated the involvement of TLR4 in acute and chronic itch models in male mice using both transgenic and pharmacological approaches. Tlr4 mice exhibited normal acute itch induced by compound 48/80 and chloroquine, but these mice showed substantial reductions in scratching in chronic itch models of dry skin, induced by acetone and diethylether followed by water (AEW), contact dermatitis, and allergic contact dermatitis on the neck. Intrathecal (spinal) inhibition of TLR4 with lipopolysaccharide Rhodobacter sphaeroides did not affect acute itch but suppressed AEW-induced chronic itch. Compound 48/80 and AEW also produced robust alloknesis, a touch-elicited itch in wild-type mice, which was suppressed by intrathecal lipopolysaccharide R sphaeroides and Tlr4 deletion. Acetone and diethylether followed by water induced persistent upregulation of Tlr4 mRNA and increased TLR4 expression in GFAP-expressing astrocytes in spinal cord dorsal horn. Acetone and diethylether followed by water also induced TLR4-dependent astrogliosis (GFAP upregulation) in spinal cord. Intrathecal injection of astroglial inhibitor L-α-aminoadipate reduced AEW-induced chronic itch and alloknesis without affecting acute itch. Spinal TLR4 was also necessary for AEW-induced chronic itch in the cheek model. Interestingly, scratching plays an essential role in spinal astrogliosis because AEW-induced astrogliosis was abrogated by putting Elizabethan collars on the neck to prevent scratching the itchy skin. Our findings suggest that spinal TLR4 signaling is important for spinal astrocyte activation and astrogliosis that may underlie alloknesis and chronic itch. PMID:26645545

  2. Cracking the Toll-like receptor code in fungal infections

    Cunha, Cristina; Romani, Luigina; Carvalho, Agostinho

    2010-01-01

    Innate control of fungal infection requires the specific recognition of invariant fungal molecular structures by a variety of innate immune receptors, including Toll-like receptors. In addition to the role in inducing protective immune responses, Toll-like receptor engagement may paradoxically favor fungal infections, by inducing inflammatory pathology and impairing antifungal immunity. Although the dissection of complex genetic traits modulating susceptibility to fungal infections is complex...

  3. The Expression of Toll-like Receptors in Dermatological Diseases and the Therapeutic Effect of Current and Newer Topical Toll-like Receptor Modulators

    Valins, Whitney; Amini, Sadegh; Berman, Brian

    2010-01-01

    Toll-like receptors are a group of glycoproteins located mostly in cellular membranes, capable of recognizing certain molecules in exogenous microorganisms and initiating immune responses against them through the activation of several intracellular signaling pathways. Toll-like receptors can be stimulated when an inflammatory reaction is needed for the treatment of conditions, such as viral infections or skin cancer, or can be inhibited when a reduction of inflammation is necessary for the tr...

  4. Curcumin attenuates renal ischemia reperfusion injury in mice by inhibiting the activation of toll-like receptor 4 signaling

    Di-ying WU

    2012-07-01

    -L 135.8±15.2, CM-H 125.6±14.6pg/ml; P < 0.05 or P < 0.01. Conclusion Curcumin can ameliorate renal IR injury in mice, which is attributable to inhibition of the activation of Toll-like receptor 4 signaling.

  5. Toll-like receptor 4 modulates skeletal muscle substrate metabolism

    Frisard, Madlyn I.; McMillan, Ryan P.; Marchand, Julie; Wahlberg, Kristin A.; Wu, Yaru; Voelker, Kevin A.; Heilbronn, Leonie; Haynie, Kimberly; Muoio, Brendan; Li, Liwu; Hulver, Matthew W.

    2010-01-01

    Toll-like receptor 4 (TLR4), a protein integral to innate immunity, is elevated in skeletal muscle of obese and type 2 diabetic humans and has been implicated in the development of lipid-induced insulin resistance. The purpose of this study was to examine the role of TLR4 as a modulator of basal (non-insulin-stimulated) substrate metabolism in skeletal muscle with the hypothesis that its activation would result in reduced fatty acid oxidation and increased partitioning of fatty acids toward n...

  6. Different activations of toll-like receptors and antimicrobial peptides in chronic rhinosinusitis with or without nasal polyposis.

    Hirschberg, Andor; Kiss, Maria; Kadocsa, Edit; Polyanka, Hilda; Szabo, Kornelia; Razga, Zsolt; Bella, Zsolt; Tiszlavicz, Laszlo; Kemeny, Lajos

    2016-07-01

    Both up- and down-regulation of the Toll-like receptors (TLRs) and antimicrobial peptides (AMPs) of the sinonasal mucosa have already been associated with the pathogenesis of chronic rhinosinusitis with (CRSwNP) or without (CRSsNP) nasal polyps. The objective of this study was to determine the expression of all known TLR and several AMP genes and some selected proteins in association with allergy, asthma and aspirin intolerance (ASA) in CRS subgroups. RT-PCR was applied to measure the mRNA expressions of 10 TLRs, four defensins, lysozyme, cathelicidin and lactoferrin (LTF) in sinonasal samples from patients with CRSsNP (n = 19), CRSwNP [ASA(-): 17; ASA(+): 7] and in control subjects (n = 12). Protein expressions were detected with immunohistochemistry (n = 10). Statistical analysis was done with the Kruskal-Wallis ANOVA, Mann-Whitney U, and Student t test. TLR2, TLR5, TLR6, TLR7, TLR8, TLR9, β-defensins 1 and 4, cathelicidin and LTF mRNA expressions were significantly (p < 0.05) increased in CRSwNP, whereas only TLR2 and LTF were up-regulated in CRSsNP compared to controls. There was no statistical difference in respect of allergy, aspirin intolerance and smoking between CRSsNP, ASA(-) and ASA(+) CRSwNP patients. TLR2, TLR3, TLR4, LTF, β defensin 2 and lysozyme protein expressions were found to be elevated in macrophages of CRSwNP samples (p < 0.05). Gene expression analysis showed markedly different expressions in CRSwNP (6 out of 10 TLR and 4 out of 7 AMP genes were up-regulated) compared to CRSsNP (1/10, 1/7). The distinct activation of the innate immunity may support the concept that CRSsNP and CRSwNP are different subtypes of CRS. These findings were found to be independent from allergy, asthma, smoking, aspirin intolerance and systemic steroid application. PMID:26518209

  7. Glucuronic acid and the ethanol metabolite ethyl-glucuronide cause toll-like receptor 4 activation and enhanced pain.

    Lewis, Susannah S; Hutchinson, Mark R; Zhang, Yingning; Hund, Dana K; Maier, Steven F; Rice, Kenner C; Watkins, Linda R

    2013-05-01

    We have previously observed that the non-opioid morphine metabolite, morphine-3-glucuronide, enhances pain via a toll-like receptor 4 (TLR4) dependent mechanism. The present studies were undertaken to determine whether TLR4-dependent pain enhancement generalizes to other classes of glucuronide metabolites. In silico modeling predicted that glucuronic acid alone and ethyl glucuronide, a minor but long-lasting ethanol metabolite, would dock to the same MD-2 portion of the TLR4 receptor complex previously characterized as the docking site for morphine-3-glucuronide. Glucuronic acid, ethyl glucuronide and ethanol all caused an increase in TLR4-dependent reporter protein expression in a cell line transfected with TLR4 and associated co-signaling molecules. Glucuronic acid-, ethyl glucuronide-, and ethanol-induced increases in TLR4 signaling were blocked by the TLR4 antagonists LPS-RS and (+)-naloxone. Glucuronic acid and ethyl glucuronide both caused allodynia following intrathecal injection in rats, which was blocked by intrathecal co-administration of the TLR4 antagonist LPS-RS. The finding that ethyl glucuronide can cause TLR4-dependent pain could have implications for human conditions such as hangover headache and alcohol withdrawal hyperalgesia, as well as suggesting that other classes of glucuronide metabolites could have similar effects. PMID:23348028

  8. DMPD: Translational mini-review series on Toll-like receptors: networks regulated byToll-like receptors mediate innate and adaptive immunity. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17223959 Translational mini-review series on Toll-like receptors: networks regulate...ol. 2007 Feb;147(2):199-207. (.png) (.svg) (.html) (.csml) Show Translational mini-review series on Toll-like receptors: networks... immunity. PubmedID 17223959 Title Translational mini-review series on Toll-like receptors: networks regulat

  9. Toll-like receptors as therapeutic targets in cystic fibrosis.

    Greene, Catherine M

    2008-12-01

    Background: Toll-like receptors (TLRs) are pattern recognition receptors that act as a first-line of defence in the innate immune response by recognising and responding to conserved molecular patterns in microbial factors and endogenous danger signals. Cystic fibrosis (CF)-affected airways represent a milieu potentially rich in TLR agonists and the chronic inflammatory phenotype evident in CF airway epithelial cells is probably due in large part to activation of TLRs. Objective\\/methods: To examine the prospects of developing novel therapies for CF by targeting TLRs. We outline the expression and function of TLRs and explore the therapeutic potential of naturally-occurring and synthetic TLR inhibitors for CF. Results\\/conclusion: Modulation of TLRs has therapeutic potential for the inflammatory lung manifestations of CF.

  10. Toll-like receptors in brain development and homeostasis

    Larsen, Peter H; Holm, Thomas Hellesøe; Owens, Trevor

    2007-01-01

    Toll-like receptors (TLRs) are best known as initiators of the innate immune response to pathogens. Recent reports now reveal intriguing roles for TLRs in the central nervous system (CNS). These include the regulation of neuroinflammation and of neurite outgrowth. The archetypal Toll protein in...

  11. MAPPING OF TOLL LIKE RECEPTOR (TLR) GENES IN RAINBOW TROUT

    Toll-like receptors (TLRs) are a family of transmembrane proteins that recognize conserved pathogen structures to induce innate immune effector molecules. In vertebrates, TLRs can distinguish among classes of pathogens and serve an important role in orchestrating the appropriate adaptive immune resp...

  12. Toll-like receptor polymorphisms in allogeneic hematopoietic cell transplantation

    Kornblit, Brian; Enevold, Christian; Wang, Tao; Spellman, Stephen; Haagenson, Mike; Lee, Stephanie J; Müller, Klaus

    2014-01-01

    To assess the impact of the genetic variation in toll-like receptors (TLRs) on outcome after allogeneic myeloablative conditioning hematopoietic cell transplantation (HCT), we investigated 29 single nucleotide polymorphisms across 10 TLRs in 816 patients and donors. Only donor genotype of TLR8 rs...... of TLR8 rs3764879 of the donor is associated with outcome after myeloablative conditioned allogeneic HCT....

  13. Toll-like receptors as sensors of pathogens.

    Hallman, M; Rämet, M; Ezekowitz, R A

    2001-09-01

    Initial recognition of microbes, as they enter the body, is based on germ line-encoded pattern recognition receptors that selectively bind to essential components of pathogens. This allows the body to respond immediately to the microbial invasion before the development of active immunity. The signal-transducing receptors that trigger the acute inflammatory cascade have been elusive until very recently. On the basis of their genetic similarity to the Toll signaling pathway in Drosophila, mammalian Toll-like receptors (TLRs) have been identified. By now, nine transmembrane proteins in the TLR family have been described. Mammalian TLR4 is the signal-transducing receptor activated by the bacterial lipopolysaccharide. The activation of TLR4 leads to DNA binding of the transcription factor NF-kappaB, resulting in activation of the inflammatory cascade. Activation of other TLRs is likely to have similar consequences. TLR2 mediates the host response to Gram-positive bacteria and yeast. TLR1 and TLR6 may participate in the activation of macrophages by Gram-positive bacteria, whereas TLR9 appears to respond to a specific sequence of bacterial DNA. The TLRs that control the onset of an acute inflammatory response are critical antecedents for the development of adaptive acquired immunity. Genetic and developmental variation in the expression of microbial pattern recognition receptors may affect the individual's predisposition to infections in childhood and may contribute to susceptibility to severe neonatal inflammatory diseases, allergies, and autoimmune diseases. PMID:11518816

  14. Toll-Like Receptors in Leishmania Infections: Guardians or Promoters?

    Marilia S. Faria

    2012-01-01

    Full Text Available Protozoa of the genus Leishmania cause a wide variety of pathologies ranging from self-healing skin lesions to visceral damage, depending on the parasite species. The outcome of infection depends on the quality of the adaptive immune response, which is determined by parasite factors and the host genetic background. Innate responses, resulting in the generation of mediators with anti-leishmanial activity, contribute to parasite control and help the development of efficient adaptive responses. Among those, the potential contribution of members of the Toll-like receptors (TLRs family in the control of Leishmania infections started to be investigated about a decade ago. Although most studies appoint a protective role for TLRs, there is growing evidence that in some cases, TLRs facilitate infection. This review highlights recent advances in TLR function during Leishmania infections and discusses their potential role in restraining parasite growth versus yielding disease.

  15. Reprint of: Microglial toll-like receptors and Alzheimer's disease.

    Su, Fan; Bai, Feng; Zhou, Hong; Zhang, Zhijun

    2016-07-01

    Microglial activation represents an important pathological hallmark of Alzheimer's disease (AD), and emerging data highlight the involvement of microglial toll-like receptors (TLRs) in the course of AD. TLRs have been observed to exert both beneficial and detrimental effects on AD-related pathologies, and transgenic animal models have provided direct and credible evidence for an association between TLRs and AD. Moreover, analyses of genetic polymorphisms have suggested interactions between genetic polymorphisms in TLRs and AD risk, further supporting the hypothesis that TLRs are involved in AD. In this review, we summarize the key evidence in this field. Future studies should focus on exploring the mechanisms underlying the potential roles of TLRs in AD. PMID:27255539

  16. THE IMPACT OF ANTIFUNGALS ON TOLL-LIKE RECEPTORS

    MirceaRaduMihu

    2014-03-01

    Full Text Available Fungi are increasingly recognized as major pathogens in immunocompromised individuals. The most common invasive fungal infections are caused by Candida spp., Aspergillus spp. and Cryptococcus spp. Amphotericin B has remained the cornerstone of therapy against many fulminant fungal infections but its use is limited by its multitude of side effects. Echinocandins are a newer class of antifungal drugs with activity against Candida spp. and Aspergillus spp. and constitutes an alternative to amphotericin B due to superior patient tolerability and fewer side effects. Due to their excellent bioavailability and oral availability, azoles continue to be heavily used for simple, such as fluconazole for candidal vaginitis, and complex diseases, such as voriconazole for aspergilloisis. The objective of this paper is to present current knowledge regarding the multiple interactions between the broad spectrum antifungals and the innate immune response, primarily focusing on the toll-like receptors.

  17. Current Views of Toll-Like Receptor Signaling Pathways

    Masahiro Yamamoto

    2010-01-01

    Full Text Available On microbial invasion, the host immediately evokes innate immune responses. Recent studies have demonstrated that Toll-like receptors (TLRs play crucial roles in innate responses that lead not only to the clearance of pathogens but also to the efficient establishment of acquired immunity by directly detecting molecules from microbes. In terms of intracellular TLR-mediated signaling pathways, cytoplasmic adaptor molecules containing Toll/IL-1R (TIR domains play important roles in inflammatory immune responses through the production of proinflammatory cytokines, nitric oxide, and type I interferon, and upregulation of costimulatory molecules. In this paper, we will describe our current understanding of the relationship between TLRs and their ligands derived from pathogens such as viruses, bacteria, fungi, and parasites. Moreover, we will review the historical and current literature to describe the mechanisms behind TLR-mediated activation of innate immune responses.

  18. Recruitment of Cbl-b to B cell antigen receptor couples antigen recognition to Toll-like receptor 9 activation in late endosomes.

    Margaret Veselits

    Full Text Available Casitas B-lineage lymphoma-b (Cbl-b is a ubiquitin ligase (E3 that modulates signaling by tagging molecules for degradation. It is a complex protein with multiple domains and binding partners that are not involved in ubiquitinating substrates. Herein, we demonstrate that Cbl-b, but not c-Cbl, is recruited to the clustered B cell antigen receptor (BCR and that Cbl-b is required for entry of endocytosed BCRs into late endosomes. The E3 activity of Cbl-b is not necessary for BCR endocytic trafficking. Rather, the ubiquitin associated (UBA domain is required. Furthermore, the Cbl-b UBA domain is sufficient to confer the receptor trafficking functions of Cbl-b on c-Cbl. Cbl-b is also required for entry of the Toll-like receptor 9 (TLR9 into late endosomes and for the in vitro activation of TLR9 by BCR-captured ligands. These data indicate that Cbl-b acts as a scaffolding molecule to coordinate the delivery of the BCR and TLR9 into subcellular compartments required for productively delivering BCR-captured ligands to TLR9.

  19. Rotavirus activates lymphocytes from non-obese diabetic mice by triggering toll-like receptor 7 signaling and interferon production in plasmacytoid dendritic cells.

    Jessica A Pane

    2014-03-01

    Full Text Available It has been proposed that rotavirus infection promotes the progression of genetically-predisposed children to type 1 diabetes, a chronic autoimmune disease marked by infiltration of activated lymphocytes into pancreatic islets. Non-obese diabetic (NOD mice provide a model for the human disease. Infection of adult NOD mice with rhesus monkey rotavirus (RRV accelerates diabetes onset, without evidence of pancreatic infection. Rather, RRV spreads to the pancreatic and mesenteric lymph nodes where its association with antigen-presenting cells, including dendritic cells, induces cellular maturation. RRV infection increases levels of the class I major histocompatibility complex on B cells and proinflammatory cytokine expression by T cells at these sites. In autoimmunity-resistant mice and human mononuclear cells from blood, rotavirus-exposed plasmacytoid dendritic cells contribute to bystander polyclonal B cell activation through type I interferon expression. Here we tested the hypothesis that rotavirus induces bystander activation of lymphocytes from NOD mice by provoking dendritic cell activation and proinflammatory cytokine secretion. NOD mouse splenocytes were stimulated with rotavirus and assessed for activation by flow cytometry. This stimulation activated antigen-presenting cells and B cells independently of virus strain and replicative ability. Instead, activation depended on virus dose and was prevented by blockade of virus decapsidation, inhibition of endosomal acidification and interference with signaling through Toll-like receptor 7 and the type I interferon receptor. Plasmacytoid dendritic cells were more efficiently activated than conventional dendritic cells by RRV, and contributed to the activation of B and T cells, including islet-autoreactive CD8+ T cells. Thus, a double-stranded RNA virus can induce Toll-like receptor 7 signaling, resulting in lymphocyte activation. Our findings suggest that bystander activation mediated by type I

  20. Cross-talk between toll-like receptor 4 (TLR4) and proteinase-activated receptor 2 (PAR2) is involved in vascular function

    Bucci, M; Vellecco, V; Harrington, L; Brancaleone, V; Roviezzo, F; Mattace Raso, G; Ianaro, A; Lungarella, G; De Palma, R; Meli, R; Cirino, G

    2013-01-01

    Background and Purpose Proteinase-activated receptors (PARs) and toll-like receptors (TLRs) are involved in innate immune responses. The aim of this study was to evaluate the possible cross-talk between PAR2 and TLR4 in vessels in physiological condition and how it varies following stimulation of TLR4 by using in vivo and ex vivo models. Experimental Approach Thoracic aortas were harvested from both naïve and endotoxaemic rats for in vitro studies. Arterial blood pressure was monitored in anaesthetized rats in vivo. LPS was used as a TLR4 agonist while PAR2 activating peptide (AP) was used as a PAR2 agonist. Aortas harvested from TLR4–/– mice were also used to characterize the PAR2 response. Key Results PAR2, but not TLR4, expression was enhanced in aortas of endotoxaemic rats. PAR2AP-induced vasorelaxation was increased in aortic rings of LPS-treated rats. TLR4 inhibitors, curcumine and resveratrol, reduced PAR2AP-induced vasorelaxation and PAR2AP-induced hypotension in both naïve and endotoxaemic rats. Finally, in aortic rings from TLR4–/– mice, the expression of PAR2 was reduced and the PAR2AP-induced vasodilatation impaired compared with those from wild-type mice and both resveratrol and curcumine were ineffective. Conclusions and Implications Cross-talk between PAR2 and TLR4 contributes to vascular homeostasis. PMID:22957757

  1. Brain interleukin-1β and the intrinsic receptor antagonist control peripheral Toll-like receptor 3-mediated suppression of spontaneous activity in rats.

    Masanori Yamato

    Full Text Available During acute viral infections such as influenza, humans often experience not only transient fever, but also prolonged fatigue or depressive feelings with a decrease in social activity for days or weeks. These feelings are thought to be due to neuroinflammation in the brain. Recent studies have suggested that chronic neuroinflammation is a precipitating event of various neurological disorders, but the mechanism determining the duration of neuroinflammation has not been elucidated. In this study, neuroinflammation was induced by intraperitoneal injection of polyriboinosinic:polyribocytidylic acid (poly I:C, a Toll-like receptor-3 agonist that mimics viral infection in male Sprague-Dawley rats, and then investigated how the neuroinflammation shift from acute to the chronic state. The rats showed transient fever and prolonged suppression of spontaneous activity for several days following poly I:C injection. NS-398, a cyclooxygenase-2 inhibitor, completely prevented fever, but did not improve spontaneous activity, indicating that suppression of spontaneous activity was not induced by the arachidonate cascade that generated the fever. The animals overexpressed interleukin (IL-1β and IL-1 receptor antagonist (IL-1ra in the brain including the cerebral cortex. Blocking the IL-1 receptor in the brain by intracerebroventricular (i.c.v. infusion of recombinant IL-1ra completely blocked the poly I:C-induced suppression of spontaneous activity and attenuated amplification of brain interferon (IFN-α expression, which has been reported to produce fatigue-like behavior by suppressing the serotonergic system. Furthermore, i.c.v. infusion of neutralizing antibody for IL-1ra prolonged recovery from suppression of spontaneous activity. Our findings indicated that IL-1β is the key trigger of neuroinflammation and that IL-1ra prevents the neuroinflammation entering the chronic state.

  2. Direct and Indirect Role of Toll-Like Receptors in T Cell Mediated Immunity

    DamoXu; HaiyingLiu; MousaKomai-Koma

    2004-01-01

    Toll-like receptors (TLR) are pathogen-associated molecular patterns (PAMPs) recognition receptors that play an important role in protective immunity against infection and inflammation. They act as central integrators of a wide variety of signals, responding to diverse agonists of microbial products. Stimulation of Toll-like receptors by microbial products leads to signaling pathways that activate not only innate, but also adaptive immunity by APC dependent or independent mechanisms. Recent evidence revealed that TLR signals played a determining role in the skewing of naive T cells towards either Thl or Th2 responses. Activation of Toll-like receptors also directly or indirectly influences regulatory T cell functions. Therefore, TLRs are required in both immune activation and immune regulation. Study of TLRs has significantly enhanced our understanding of innate and adaptive immune responses and provides novel therapeutic approaches against infectious and inflammatory diseases. Cellular & Molecular Immunology.

  3. Direct and Indirect Role of Toll-Like Receptors in T Cell Mediated Immunity

    Damo Xu; Haiying Liu; Mousa Komai-Koma

    2004-01-01

    Toll-like receptors (TLR) are pathogen-associated molecular patterns (PAMPs) recognition receptors that play an important role in protective immunity against infection and inflammation. They act as central integrators of a wide variety of signals, responding to diverse agonists of microbial products. Stimulation of Toll-like receptors by microbial products leads to signaling pathways that activate not only innate, but also adaptive immunity by APC dependent or independent mechanisms. Recent evidence revealed that TLR signals played a determining role in the skewing of na(i)ve T cells towards either Th1 or Th2 responses. Activation of Toll-like receptors also directly or indirectly influences regulatory T cell functions. Therefore, TLRs are required in both immune activation and immune regulation. Study of TLRs has significantly enhanced our understanding of innate and adaptive immune responses and provides novel therapeutic approaches against infectious and inflammatory diseases.

  4. Pan-Vertebrate Toll-Like Receptors During Evolution

    Oshiumi, Hiroyuki; Matsuo, Aya; Matsumoto, Misako; Seya, Tsukasa

    2008-01-01

    Human toll-like receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs) to raise innate immune responses. The human TLR family was discovered because of its sequence similarity to fruit fly (Drosophila) Toll, which is involved in an anti-fungal response. In this review, we focus on the origin of the vertebrate TLR family highlighted through functional and phylogenetic analyses of TLRs in non-mammalian vertebrates. Recent extensive genome projects revealed that teleosts conta...

  5. Intervention on toll-like receptors in pancreatic cancer

    Vaz, Juan; Andersson, Roland

    2014-01-01

    Pancreatic ductal adenocarcinoma (PDA) is a devastating disease with pronounced morbidity and a high mortality rate. Currently available treatments lack convincing cost-efficiency determinations and are in most cases not associated with relevant success rate. Experimental stimulation of the immune system in murine PDA models has revealed some promising results. Toll-like receptors (TLRs) are pillars of the immune system that have been linked to several forms of malignancy, including lung, bre...

  6. The evolution of vertebrate Toll-like receptors

    Roach, Jared C.; Glusman, Gustavo; Rowen, Lee; Kaur, Amardeep; Purcell, Maureen K.; Smith, Kelly D.; Hood, Leroy E.; Aderem, Alan

    2005-01-01

    The complete sequences of Takifugu Toll-like receptor (TLR) loci and gene predictions from many draft genomes enable comprehensive molecular phylogenetic analysis. Strong selective pressure for recognition of and response to pathogen-associated molecular patterns has maintained a largely unchanging TLR recognition in all vertebrates. There are six major families of vertebrate TLRs. This repertoire is distinct from that of invertebrates. TLRs within a family recognize a general class of pathog...

  7. Toll-like receptor sensing of human herpesvirus infection

    John A West; Gregory, Sean M.; Damania, Blossom

    2012-01-01

    Toll-like receptors (TLRs) are evolutionarily conserved pathogen sensors that constitute the first line of defense in the human immune system. Herpesviruses are prevalent throughout the world and cause significant disease in the human population. Sensing of herpesviruses via TLRs has only been documented in the last 10 years and our understanding of the relationship between these sentinels of the immune system and herpesvirus infection has already provided great insight into how the host cell...

  8. Human herpesvirus 6 infection impairs Toll-like receptor signaling

    Ochi Toshiki; Suemori Koichiro; An Jun; Fujiwara Hiroshi; Tanimoto Kazushi; Murakami Yuichi; Hasegawa Hitoshi; Yasukawa Masaki

    2010-01-01

    Abstract Human herpesvirus 6 (HHV-6) has a tropism for immunocompetent cells, including T lymphocytes, monocytes/macrophages, and dendritic cells (DCs) suggesting that HHV-6 infection affects the immunosurveillance system. Toll-like receptor (TLR) system plays an important role in innate immunity against various pathogens. In the present study, we investigated the effect of HHV-6 infection on the expression and intracellular signaling of TLRs in DCs. Although expression levels of TLRs were no...

  9. Neu1 desialylation of sialyl alpha-2,3-linked beta-galactosyl residues of TOLL-like receptor 4 is essential for receptor activation and cellular signaling.

    Amith, Schammim Ray; Jayanth, Preethi; Franchuk, Susan; Finlay, Trisha; Seyrantepe, Volkan; Beyaert, Rudi; Pshezhetsky, Alexey V; Szewczuk, Myron R

    2010-02-01

    The ectodomain of TOLL-like receptors (TLR) is highly glycosylated with several N-linked gylcosylation sites located in the inner concave surface. The precise role of these sugar N-glycans in TLR receptor activation is unknown. Recently, we have shown that Neu1 sialidase and not Neu2, -3 and -4 forms a complex with TLR-2, -3 and -4 receptors on the cell-surface membrane of naïve and activated macrophage cells (Glycoconj J DOI 10.1007/s10719-009-9239-8). Activation of Neu1 is induced by TLR ligands binding to their respective receptors. Here, we show that endotoxin lipopolysaccharide (LPS)-induced MyD88/TLR4 complex formation and subsequent NFkappaB activation is dependent on the removal of alpha-2,3-sialyl residue linked to beta-galactoside of TLR4 by the Neu1 activity associated with LPS-stimulated live primary macrophage cells, macrophage and dendritic cell lines but not with primary Neu1-deficient macrophage cells. Exogenous alpha-2,3 sialyl specific neuraminidase (Streptoccocus pneumoniae) and wild-type T. cruzi trans-sialidase (TS) but not the catalytically inactive mutant TSAsp98-Glu mediate TLR4 dimerization to facilitate MyD88/TLR4 complex formation and NFkappaB activation similar to those responses seen with LPS. These same TLR ligand-induced NFkappaB responses are not observed in TLR deficient HEK293 cells, but are re-established in HEK293 cells stably transfected with TLR4/MD2, and are significantly inhibited by alpha-2,3-sialyl specific Maackia amurensis (MAL-2) lectin, alpha-2,3-sialyl specific galectin-1 and neuraminidase inhibitor Tamiflu but not by alpha-2,6-sialyl specific Sambucus nigra lectin (SNA). Taken together, the findings suggest that Neu1 desialylation of alpha-2,3-sialyl residues of TLR receptors enables in removing a steric hinderance to receptor association for TLR activation and cellular signaling. PMID:19796680

  10. Toll-Like Receptor 7-Targeted Therapy in Respiratory Disease.

    Lebold, Katie M; Jacoby, David B; Drake, Matthew G

    2016-03-01

    Allergic asthma and allergic rhinitis are inflammatory diseases of the respiratory tract characterized by an excessive type-2 T helper cell (Th2) immune response. Toll-like receptor 7 (TLR7) is a single-stranded viral RNA receptor expressed in the airway that initiates a Th1 immune response and has garnered interest as a novel therapeutic target for treatment of allergic airway diseases. In animal models, synthetic TLR7 agonists reduce airway hyperreactivity, eosinophilic inflammation, and airway remodeling while decreasing Th2-associated cytokines. Furthermore, activation of TLR7 rapidly relaxes airway smooth muscle via production of nitric oxide. Thus, TLR7 has dual bronchodilator and anti-inflammatory effects. Two TLR7 ligands with promising pharmacologic profiles have entered clinical trials for the treatment of allergic rhinitis. Moreover, TLR7 agonists are potential antiviral therapies against respiratory viruses. TLR7 agonists enhance influenza vaccine efficacy and also reduce viral titers when given during an active airway infection. In this review, we examine the current data supporting TLR7 as a therapeutic target in allergic airway diseases. PMID:27226793

  11. DMPD: Toll-like receptor signal transduction. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17934330 Toll-like receptor signal transduction. Krishnan J, Selvarajoo K, Tsuchiya... M, Lee G, Choi S. Exp Mol Med. 2007 Aug 31;39(4):421-38. (.png) (.svg) (.html) (.csml) Show Toll-like receptor signal tran...sduction. PubmedID 17934330 Title Toll-like receptor signal transduction. Authors Krishnan J,

  12. DMPD: Toll like receptors and autoimmunity: a critical appraisal. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17959357 Toll like receptors and autoimmunity: a critical appraisal. Papadimitraki ...ml) Show Toll like receptors and autoimmunity: a critical appraisal. PubmedID 17959357 Title Toll like recep...tors and autoimmunity: a critical appraisal. Authors Papadimitraki ED, Bertsias G

  13. DMPD: The Toll-like receptors: analysis by forward genetic methods. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 16001129 The Toll-like receptors: analysis by forward genetic methods. Beutler B. I...mmunogenetics. 2005 Jul;57(6):385-92. (.png) (.svg) (.html) (.csml) Show The Toll-like receptors: analysis by forward genetic methods.... PubmedID 16001129 Title The Toll-like receptors: analysis by forward genetic methods

  14. DMPD: Endogenous ligands of Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15178705 Endogenous ligands of Toll-like receptors. Tsan MF, Gao B. J Leukoc Biol. ...2004 Sep;76(3):514-9. Epub 2004 Jun 3. (.png) (.svg) (.html) (.csml) Show Endogenous ligands of Toll-like re...ceptors. PubmedID 15178705 Title Endogenous ligands of Toll-like receptors. Authors Tsan MF, Gao B. Publicat

  15. DMPD: Toll-like receptors and Type I interferons. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17395581 Toll-like receptors and Type I interferons. Uematsu S, Akira S. J Biol Che...m. 2007 May 25;282(21):15319-23. Epub 2007 Mar 29. (.png) (.svg) (.html) (.csml) Show Toll-like receptors and Type... I interferons. PubmedID 17395581 Title Toll-like receptors and Type I interferons. Authors Uematsu S,

  16. DMPD: Viral recognition by Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17336545 Viral recognition by Toll-like receptors. Barton GM. Semin Immunol. 2007 F...eb;19(1):33-40. Epub 2007 Mar 2. (.png) (.svg) (.html) (.csml) Show Viral recognition by Toll-like receptors.... PubmedID 17336545 Title Viral recognition by Toll-like receptors. Authors Barton GM. Publication Semin Imm

  17. DMPD: Toll-like receptors regulation of viral infection and disease. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 18280610 Toll-like receptors regulation of viral infection and disease. Thompson JM...how Toll-like receptors regulation of viral infection and disease. PubmedID 18280610 Title Toll-like recepto...rs regulation of viral infection and disease. Authors Thompson JM, Iwasaki A. Pub

  18. DMPD: A Toll-like receptor in horseshoe crabs. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15199958 A Toll-like receptor in horseshoe crabs. Inamori K, Ariki S, Kawabata S. I...mmunol Rev. 2004 Apr;198:106-15. (.png) (.svg) (.html) (.csml) Show A Toll-like receptor in horseshoe crabs.... PubmedID 15199958 Title A Toll-like receptor in horseshoe crabs. Authors Inamori K, Ariki S, Kawabata S. Pu

  19. Toll-like receptor signaling in primary immune deficiencies.

    Maglione, Paul J; Simchoni, Noa; Cunningham-Rundles, Charlotte

    2015-11-01

    Toll-like receptors (TLRs) recognize common microbial or host-derived macromolecules and have important roles in early activation of the immune system. Patients with primary immune deficiencies (PIDs) affecting TLR signaling can elucidate the importance of these proteins to the human immune system. Defects in interleukin-1 receptor-associated kinase-4 and myeloid differentiation factor 88 (MyD88) lead to susceptibility to infections with bacteria, while mutations in nuclear factor-κB essential modulator (NEMO) and other downstream mediators generally induce broader susceptibility to bacteria, viruses, and fungi. In contrast, TLR3 signaling defects are specific for susceptibility to herpes simplex virus type 1 encephalitis. Other PIDs induce functional alterations of TLR signaling pathways, such as common variable immunodeficiency in which plasmacytoid dendritic cell defects enhance defective responses of B cells to shared TLR agonists. Dampening of TLR responses is seen for TLRs 2 and 4 in chronic granulomatous disease (CGD) and X-linked agammaglobulinemia (XLA). Enhanced TLR responses, meanwhile, are seen for TLRs 5 and 9 in CGD, TLRs 4, 7/8, and 9 in XLA, TLRs 2 and 4 in hyper IgE syndrome, and for most TLRs in adenosine deaminase deficiency. PMID:25930993

  20. Toll-Like Receptor 9 in Breast Cancer

    Sandholm, Jouko; Selander, Katri S.

    2014-01-01

    Toll-like receptor 9 (TLR9) is a cellular DNA receptor of the innate immune system. DNA recognition via TLR9 results in an inflammatory reaction, which eventually also activates a Th1-biased adaptive immune attack. In addition to cells of the immune system, TLR9 mRNA and protein are also widely expressed in breast cancer cell lines and in clinical breast cancer specimens. Although synthetic TLR9-ligands induce cancer cell invasion in vitro, the role of TLR9 in cancer pathophysiology has remained unclear. In the studies conducted so far, tumor TLR9 expression has been shown to have prognostic significance only in patients that have triple-negative breast cancer (TNBC). Specifically, high tumor TLR9 expression predicts good prognosis among TNBC patients. Pre-clinical studies suggest that TLR9 expression may affect tumor immunophenotype and contribute to the immunogenic benefit of chemotherapy. In this review, we discuss the possible contribution of tumor TLR9 to the pathogenesis and treatment responses in breast cancer. PMID:25101078

  1. Toll-like receptors in invertebrate innate immunity

    L Zheng

    2005-08-01

    Full Text Available Among invertebrates, innate immunity is the only defense mechanism against harmful non-self agents.In response to recognition of microbial pattern molecules, Drosophila melanogaster activates either theToll or Imd pathway, leading to the translocation of NF-kB (or Rel transcription factors from the cytoplasmto the nucleus and the subsequent production of antimicrobial peptides, which provide systemic innateimmunity. Toll-like receptors (TLRs are characterized by an extracellular leucine rich repeat (LRRdomain and an intracellular Toll/interleukin-1 receptor (TIR domain. TLRs are found from cnidarians tomammals. Here we argue that TLR mediated innate immunity developed during an early stage ofevolution when organisms acquired a body cavity. This is supported by the distributions of TLR and Relgenes in the animal kingdom. Further, TLR mediated immunity appears to have developed independentlyin invertebrates and vertebrates. Recent studies have shown that microbial molecules, with the potentialto signal through TLR, can be beneficial to host survival. Studies on this signaling pathway could opendoors to a better understanding of the origins of innate immunity in invertebrates and potentialtransmission blocking strategies aimed at ameliorating vector-borne diseases.

  2. Involvement of Toll-like receptors in acute radiation syndrome and radiation therapy for cancer

    Toll-like receptors (TLR) are one of pattern recognition receptors that are indispensable for antibacterial and antiviral immunity. After TLRs sense pathogen-derived components, they activate intracellular signaling pathways, which results in the induction of proinflammatory cytokines. Although it is well known that radiation therapy is one of effective cancer therapies, radiation affects immune system. Recent evidences show the involvement of TLR in acute radiation syndrome and radiation therapy for cancer. I summarize to date knowledge on the involvement of Toll-like receptors in acute radiation syndromes and radiation therapy for cancer, and discuss the effects of ionizing radiation on TLR of innate immune cells. (author)

  3. Cathepsins are required for Toll-like receptor 9 responses

    Toll-like receptors (TLR) recognize a variety of microbial products and activate defense responses. Pathogen sensing by TLR2/4 requires accessory molecules, whereas little is known about a molecule required for DNA recognition by TLR9. After endocytosis of microbes, microbial DNA is exposed and recognized by TLR9 in lysosomes. We here show that cathepsins, lysosomal cysteine proteases, are required for TLR9 responses. A cell line Ba/F3 was found to be defective in TLR9 responses despite enforced TLR9 expression. Functional cloning with Ba/F3 identified cathepsin B/L as a molecule required for TLR9 responses. The protease activity was essential for the complementing effect. TLR9 responses were also conferred by cathepsin S or F, but not by cathepsin H. TLR9-dependent B cell proliferation and CD86 upregulation were apparently downregulated by cathepsin B/L inhibitors. Cathepsin B inhibitor downregulated interaction of CpG-B with TLR9 in 293T cells. These results suggest roles for cathepsins in DNA recognition by TLR9

  4. Toll-Like Receptor 9 Agonists for Cancer Therapy

    Davide Melisi

    2014-08-01

    Full Text Available The immune system has acquired increasing importance as a key player in cancer maintenance and growth. Thus, modulating anti-tumor immune mediators has become an attractive strategy for cancer treatment. Toll-like receptors (TLRs have gradually emerged as potential targets of newer immunotherapies. TLR-9 is preferentially expressed on endosome membranes of B-cells and plasmacytoid dendritic cells (pDC and is known for its ability to stimulate specific immune reactions through the activation of inflammation-like innate responses. Several synthetic CpG oligonucleotides (ODNs have been developed as TLR-9 agonists with the aim of enhancing cancer immune surveillance. In many preclinical models, CpG ODNs were found to suppress tumor growth and proliferation both in monotherapy and in addition to chemotherapies or target therapies. TLR-9 agonists have been also tested in several clinical trials in patients with solid tumors. These agents showed good tolerability and usually met activity endpoints in early phase trials. However, they have not yet been demonstrated to significantly impact survival, neither as single agent treatments, nor in combination with chemotherapies or cancer vaccines. Further investigations in larger prospective studies are required.

  5. Activation of Human Toll-like Receptor 4 (TLR4)·Myeloid Differentiation Factor 2 (MD-2) by Hypoacylated Lipopolysaccharide from a Clinical Isolate of Burkholderia cenocepacia.

    Di Lorenzo, Flaviana; Kubik, Łukasz; Oblak, Alja; Lorè, Nicola Ivan; Cigana, Cristina; Lanzetta, Rosa; Parrilli, Michelangelo; Hamad, Mohamad A; De Soyza, Anthony; Silipo, Alba; Jerala, Roman; Bragonzi, Alessandra; Valvano, Miguel A; Martín-Santamaría, Sonsoles; Molinaro, Antonio

    2015-08-28

    Lung infection by Burkholderia species, in particular Burkholderia cenocepacia, accelerates tissue damage and increases post-lung transplant mortality in cystic fibrosis patients. Host-microbe interplay largely depends on interactions between pathogen-specific molecules and innate immune receptors such as Toll-like receptor 4 (TLR4), which recognizes the lipid A moiety of the bacterial lipopolysaccharide (LPS). The human TLR4·myeloid differentiation factor 2 (MD-2) LPS receptor complex is strongly activated by hexa-acylated lipid A and poorly activated by underacylated lipid A. Here, we report that B. cenocepacia LPS strongly activates human TLR4·MD-2 despite its lipid A having only five acyl chains. Furthermore, we show that aminoarabinose residues in lipid A contribute to TLR4-lipid A interactions, and experiments in a mouse model of LPS-induced endotoxic shock confirmed the proinflammatory potential of B. cenocepacia penta-acylated lipid A. Molecular modeling combined with mutagenesis of TLR4-MD-2 interactive surfaces suggests that longer acyl chains and the aminoarabinose residues in the B. cenocepacia lipid A allow exposure of the fifth acyl chain on the surface of MD-2 enabling interactions with TLR4 and its dimerization. Our results provide a molecular model for activation of the human TLR4·MD-2 complex by penta-acylated lipid A explaining the ability of hypoacylated B. cenocepacia LPS to promote proinflammatory responses associated with the severe pathogenicity of this opportunistic bacterium. PMID:26160169

  6. The Architecture of the TIR Domain Signalosome in the Toll-like Receptor-4 Signaling Pathway

    Emine Guven-Maiorov; Ozlem Keskin; Attila Gursoy; Carter VanWaes; Zhong Chen; Chung-Jung Tsai; Ruth Nussinov

    2015-01-01

    Scientific Reports | 5:13128 | DOI: 10.1038/srep13128 1 www.nature.com/scientificreports The Architecture of the TIR Domain Signalosome in the Toll-like Receptor-4 Signaling Pathway Emine Guven-Maiorov1,2, Ozlem Keskin1,2, Attila Gursoy2,3, Carter VanWaes4, Zhong Chen4, Chung-Jung Tsai5 & Ruth Nussinov5,6 Activated Toll-like receptors (TLRs) cluster in lipid rafts and induce pro- and anti-tumor responses. The organization of the assembly is critical to the understandin...

  7. Toll-Like Receptor 3 in Liver Diseases

    Shi Yin

    2010-01-01

    Full Text Available Toll-like receptor 3 (TLR3 is a member of the TLR family that can recognize double-stranded RNA (dsRNA, playing an important role in antiviral immunity. Recent studies have shown that TLR3 is also expressed on parenchymal and nonparenchymal cells in the liver as well as on several types of immune cells. In this review, we summarize the role of TLR3 in liver injury, inflammation, regeneration, and liver fibrosis, and discuss the implication of TLR3 in the pathogenesis of human liver diseases including viral hepatitis and autoimmune liver disease.

  8. Toll-Like Receptor Initiated Host Defense against Toxoplasma gondii

    Eric Y. Denkers

    2010-01-01

    Full Text Available Toxoplasma gondii is an intracellular pathogen notable for its ability to establish a stable host-parasite relationship amongst a wide range of host species and in a large percentage of the human population. Toll-like receptor signaling through MyD88 is a critical pathway in initiating defense against this opportunistic protozoan and may also be a mediator of pathology during immune dysfunction. Other MyD88 independent signaling pathways are also involved in the host-parasite interaction. These responses can be triggered by the parasite itself, but interactions with the intestinal microbiota add additional complexity during enteric infection.

  9. BURN-INDUCED ALTERATIONS IN TOLL-LIKE RECEPTOR-MEDIATED RESPONSES BY BRONCHOALVEOLAR LAVAGE CELLS

    Richard F. Oppeltz; Rani, Meenakshi; Zhang, Qiong; Schwacha, Martin G.

    2011-01-01

    Burn is associated with profound inflammation and activation of the innate immune system in multiple organ beds, including the lung. Similarly, toll-like receptors (TLR) are associated with innate immune activation. Nonetheless, it is unclear what impact burn has on TLR-induced inflammatory responses in the lung.

  10. Damage-associated molecular pattern activated Toll-like receptor 4 signalling modulates blood pressure in L-NAME-induced hypertension

    Sollinger, D.; Eissler, R.; Lorenz, S.; Strand, S.; Chmielewski, S.; Aoqui, C.; Schmaderer, Ch.; Bluyssen, H.; Zicha, Josef; Witzke, O.; Scherer, E.; Lutz, J.; Heemann, U.; Baumann, M.

    2014-01-01

    Roč. 101, č. 3 (2014), s. 464-472. ISSN 0008-6363 R&D Projects: GA ČR(CZ) GA305/09/0336 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : innate immunity * Toll-like receptors * reactive oxygen species * vascular contractility Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 5.940, year: 2014

  11. Paliperidone Prevents Brain Toll-Like Receptor 4 Pathway Activation and Neuroinflammation in Rat Models of Acute and Chronic Restraint Stress

    MacDowell, KS; Caso, JR; Martín-Hernández, D; Madrigal, JL; Leza, JC.; B. García-Bueno

    2015-01-01

    Background: Alterations in the innate immune/inflammatory system have been proposed to underlie the pathophysiology of psychotic disease, but the mechanisms implicated remain elusive. The main agents of the innate immunity are the family of toll-like receptors (TLRs), which detect circulating pathogen-associated molecular patterns and endogenous damage-associated molecular patterns (DAMPS). Current antipsychotics are able to modulate pro- and anti-inflammatory pathways, but their actions on T...

  12. Toll-Like Receptor Gene Expression during Trichinella spiralis Infection.

    Kim, Sin; Park, Mi Kyung; Yu, Hak Sun

    2015-08-01

    In Trichinella spiralis infection, type 2 helper T (Th2) cell-related and regulatory T (Treg) cell-related immune responses are the most important immune events. In order to clarify which Toll-like receptors (TLRs) are closely associated with these responses, we analyzed the expression of mouse TLR genes in the small intestine and muscle tissue during T. spiralis infection. In addition, the expression of several chemokine- and cytokine-encoding genes, which are related to Th2 and Treg cell mediated immune responses, were analyzed in mouse embryonic fibroblasts (MEFs) isolated from myeloid differentiation factor 88 (MyD88)/TIR-associated proteins (TIRAP) and Toll receptor-associated activator of interferons (TRIF) adapter protein deficient and wild type (WT) mice. The results showed significantly increased TLR4 and TLR9 gene expression in the small intestine after 2 weeks of T. spiralis infection. In the muscle, TLR1, TLR2, TLR5, and TLR9 gene expression significantly increased after 4 weeks of infection. Only the expression of the TLR4 and TLR9 genes was significantly elevated in WT MEF cells after treatment with excretory-secretory (ES) proteins. Gene expression for Th2 chemokine genes were highly enhanced by ES proteins in WT MEF cells, while this elevation was slightly reduced in MyD88/TIRAP(-/-) MEF cells, and quite substantially decreased in TRIF(-/-) MEF cells. In contrast, IL-10 and TGF-β expression levels were not elevated in MyD88/TIRAP(-/-) MEF cells. In conclusion, we suggest that TLR4 and TLR9 might be closely linked to Th2 cell and Treg cell mediated immune responses, although additional data are needed to convincingly prove this observation. PMID:26323841

  13. MyD88-dependent and independent pathways of Toll-Like Receptors are engaged in biological activity of Triptolide in ligand-stimulated macrophages

    Dorn Ruth

    2010-04-01

    Full Text Available Abstract Background Triptolide is a diterpene triepoxide from the Chinese medicinal plant Tripterygium wilfordii Hook F., with known anti-inflammatory, immunosuppressive and anti-cancer properties. Results Here we report the expression profile of immune signaling genes modulated by triptolide in LPS induced mouse macrophages. In an array study triptolide treatment modulated expression of 22.5% of one hundred and ninety five immune signaling genes that included Toll-like receptors (TLRs. TLRs elicit immune responses through their coupling with intracellular adaptor molecules, MyD88 and TRIF. Although it is known that triptolide inhibits NFκB activation and other signaling pathways downstream of TLRs, involvement of TLR cascade in triptolide activity was not reported. In this study, we show that triptolide suppresses expression of proinflammatory downstream effectors induced specifically by different TLR agonists. Also, the suppressive effect of triptolide on TLR-induced NFκB activation was observed when either MyD88 or TRIF was knocked out, confirming that both MyD88 and TRIF mediated NFκB activation may be inhibited by triptolide. Within the TLR cascade triptolide downregulates TLR4 and TRIF proteins. Conclusions This study reveals involvement of TLR signaling in triptolide activity and further increases understanding of how triptolide activity may downregulate NFκB activation during inflammatory conditions.

  14. A bacterial carbohydrate links innate and adaptive responses through Toll-like receptor 2

    Wang, Qun; McLoughlin, Rachel M.; Cobb, Brian A; Charrel-Dennis, Marie; Zaleski, Kathleen J.; Golenbock, Douglas; Tzianabos, Arthur O.; Kasper, Dennis L.

    2006-01-01

    Commensalism is critical to a healthy Th1/Th2 cell balance. Polysaccharide A (PSA), which is produced by the intestinal commensal Bacteroides fragilis, activates CD4+ T cells, resulting in a Th1 response correcting the Th2 cell skew of germ-free mice. We identify Toll-like receptors as crucial to the convergence of innate and adaptive responses stimulated by PSA. Optimization of the Th1 cytokine interferon-γ in PSA-stimulated dendritic cell–CD4+ T cell co-cultures depends on both Toll-like re...

  15. Toll-like receptor agonist augments virus-like particle-mediated protection from Ebola virus with transient immune activation.

    Karen A O Martins

    Full Text Available Identifying safe and effective adjuvants is critical for the advanced development of protein-based vaccines. Pattern recognition receptor (PRR agonists are increasingly being explored as potential adjuvants, but there is concern that the efficacy of these molecules may be dependent on potentially dangerous levels of non-specific immune activation. The filovirus virus-like particle (VLP vaccine protects mice, guinea pigs, and nonhuman primates from viral challenge. In this study, we explored the impact of a stabilized dsRNA mimic, polyICLC, on VLP vaccination of C57BL/6 mice and Hartley guinea pigs. We show that at dose levels as low as 100 ng, the adjuvant increased the efficacy of the vaccine in mice. Antigen-specific, polyfunctional CD4 and CD8 T cell responses and antibody responses increased significantly upon inclusion of adjuvant. To determine whether the efficacy of polyICLC correlated with systemic immune activation, we examined serum cytokine levels and cellular activation in the draining lymph node. PolyICLC administration was associated with increases in TNFα, IL6, MCP1, MIP1α, KC, and MIP1β levels in the periphery and with the activation of dendritic cells (DCs, NK cells, and B cells. However, this activation resolved within 24 to 72 hours at efficacious adjuvant dose levels. These studies are the first to examine the polyICLC-induced enhancement of antigen-specific immune responses in the context of non-specific immune activation, and they provide a framework from which to consider adjuvant dose levels.

  16. DMPD: Nuclear factor-kappaB: activation and regulation during toll-like receptorsignaling. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17349209 Nuclear factor-kappaB: activation and regulation during toll-like receptor...signaling. Carmody RJ, Chen YH. Cell Mol Immunol. 2007 Feb;4(1):31-41. (.png) (.svg) (.html) (.csml) Show Nuclear factor...-kappaB: activation and regulation during toll-like receptorsignaling. PubmedID 17349209 Title Nuclear factor

  17. Toll-like receptor gene polymorphisms are associated with allergic rhinitis: a case control study

    Nilsson Daniel; Andiappan Anand; Halldén Christer; Yun Wang; Säll Torbjörn; Tim Chew; Cardell Lars-Olaf

    2012-01-01

    Abstract Background The Toll-like receptor proteins are important in host defense and initiation of the innate and adaptive immune responses. A number of studies have identified associations between genetic variation in the Toll-like receptor genes and allergic disorders such as asthma and allergic rhinitis. The present study aim to search for genetic variation associated with allergic rhinitis in the Toll-like receptor genes. Methods A first association analysis genotyped 73 SNPs in 182 case...

  18. Activation of eosinophils via Toll-like receptor (TLR3, TLR7 and TLR9: link between viral infection and asthma?

    Anne Månsson

    2008-04-01

    Full Text Available Asthma is disease characterized by a massive accumulation of eosinophils that release an array of tissue-damaging mediators. Respiratory viral infections are thought to be a leading cause of exacerbations of asthma. One possible explanation might be a direct activation of viral components through Toll-like receptors (TLRs, a receptor family comprising 10 different pathogen-recognizing members (TLR1-TLR10. The virus-recognizing TLRs are TLR3, TLR7/8 and TLR9, which respond to viral dsRNA, ssRNA and CpG-DNA. The present study aimed to investigate the expression of these TLRs and their functions in human eosinophils. Eosinophils were isolated from peripheral blood using magnetic beads (purity >97%. Cells were incubated with or without poly(I:C, R-837 or CpG alone, the synthetic ligands of TLR3, TLR7 and TLR9, respectively, or combined with IL-4 or histamine. Flow cytometry, and ELISA were used to analyze expression of TLRs and various surface markers, viability and secretion of inflammatory mediators. Eosinophils expressed proteins for TLR3, TLR7 and TLR9. Poly(I:C, R-837 and CpG prolonged survival, up-regulated expression of the adhesion molecule CD11b and increased secretion of IL-8 compared to unstimulated controls. These effects were affected by the presence of IL-4 and histamine. This study shows that several viral products directly activate eosinophils through their TLRs. Since eosinophils are central in asthma, the TLR system may be an important mechanism of eosinophil activation linking viral infections with exacerbations. Consequently, this system represents a future clinical target for the resolution of asthmatic disease.

  19. The application of Toll like receptors for cancer therapy

    Eui Young So, Toru Ouchi

    2010-01-01

    Full Text Available Toll-like receptor (TLR proteins play key roles in immune responses against infection. Using TLR proteins, host can recognize the conserved molecular structures found in pathogens called pathogen-associated molecular patterns (PAMPs. At the same time, some TLRs are able to detect specific host molecules, such as high-mobility group box protein 1 (HMGB1 and heat shock proteins (hsp, and lead to inflammatory responses. Thus, it has been suggested that TLRs are involved in the development of many pathogenic conditions. Recent advances in TLR-related research not only provide us with scientific information, but also show the therapeutic potential against diseases, such as autoimmune disease and cancer. In this mini review, we demonstrate how TLRs pathways could be involved in cancer development and their therapeutic application, and discuss recent patentable subjects, in particular, that are targeting this unique pathway.

  20. Toll-like receptors as targets for immune disorders.

    Keogh, Brian

    2012-02-01

    Since the identification of the first Toll-like receptor (TLR) in humans in 1997, understanding of the molecular basis for innate immunity has increased significantly. The TLR family and downstream signalling pathways have been extensively characterised, There is now significant evidence suggesting a role for TLRs in human inflammatory and immune diseases such as rheumatoid arthritis, diabetes, allergy\\/asthma and atherosclerosis. Various approaches have been taken to identify novel therapeutic agents targeting TLRs including biologics, small molecules and nucleic acid-based drugs. Several are now being evaluated in the clinic and showing promise against various diseases. This review paper outlines the recent advances in the understanding of TLR biology and highlights novel TLR agonists and antagonists in development for the treatment of immune diseases.

  1. Micrococcus luteus Teichuronic Acids Activate Human and Murine Monocytic Cells in a CD14- and Toll-Like Receptor 4-Dependent Manner

    YANG, SHUHUA; Sugawara, Shunji; Monodane, Toshihiko; Nishijima, Masahiro; Adachi, Yoshiyuki; Akashi, Sachiko; Miyake, Kensuke; Hase, Sumihiro; Takada, Haruhiko

    2001-01-01

    Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerly Micrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4–12, 2001). In this study, we found that purified TUA (p-TUA) i...

  2. A distinct profile of tryptophan metabolism along the kynurenine pathway downstream of Toll-like receptor activation in irritable bowel syndrome

    GerardClarke

    2012-05-01

    Full Text Available Irritable bowel syndrome (IBS, a disorder of the brain-gut axis, is characterised by the absence of reliable biological markers. Tryptophan is an essential amino acid that serves as a precursor to serotonin but which can alternatively be metabolised along the kynurenine pathway leading to the production of other neuroactive agents. We previously reported an increased degradation of tryptophan along this immunoresponsive pathway in IBS. Recently, altered cytokine production following activation of specific members of the toll-like receptor (TLR family (TLR1-9 has also been demonstrated in IBS. However, the relationship between TLR activation and kynurenine pathway activity in IBS is unknown. In this study, we investigated whether activation of specific TLRs elicits exaggerated kynurenine production in IBS patients compared to controls. Whole blood from IBS patients and healthy controls was cultured with a panel of nine different TLR agonists for 24 hours. Cell culture supernatants were then analysed for both tryptophan and kynurenine concentrations, as were plasma samples from both cohorts. IBS subjects had an elevated plasma kynurenine:tryptophan ratio compared to healthy controls. Furthermore, we demonstrated a differential downstream profile of kynurenine production subsequent to TLR activation in IBS patients compared to healthy controls. This profile included alterations at TLR1/2, TLR2, TLR3, TLR5, TLR7 and TLR8. Our data expands on our previous understanding of altered tryptophan metabolism in IBS and suggests that measurement of tryptophan metabolites downstream of TLR activation may ultimately find utility as components of a biomarker panel to aid gastroenterologists in the diagnosis of IBS. Furthermore, these studies implicate the modulation of TLRs as means through which aberrant tryptophan metabolism along the kynurenine pathway can be controlled, a novel potential therapeutic strategy in this and other disorders.

  3. Mycobacterium paratuberculosis CobT activates dendritic cells via engagement of Toll-like receptor 4 resulting in Th1 cell expansion.

    Byun, Eui-Hong; Kim, Woo Sik; Kim, Jong-Seok; Won, Choul-Jae; Choi, Han-Gyu; Kim, Hwa-Jung; Cho, Sang-Nae; Lee, Keehoon; Zhang, Tiejun; Hur, Gang Min; Shin, Sung Jae

    2012-11-01

    Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne disease in animals and MAP involvement in human Crohn disease has been recently emphasized. Evidence from M. tuberculosis studies suggests mycobacterial proteins activate dendritic cells (DCs) via Toll-like receptor (TLR) 4, eventually determining the fate of immune responses. Here, we investigated whether MAP CobT contributes to the development of T cell immunity through the activation of DCs. MAP CobT recognizes TLR4, and induces DC maturation and activation via the MyD88 and TRIF signaling cascades, which are followed by MAP kinases and NF-κB. We further found that MAP CobT-treated DCs activated naive T cells, effectively polarized CD4(+) and CD8(+) T cells to secrete IFN-γ and IL-2, but not IL-4 and IL-10, and induced T cell proliferation. These data indicate that MAP CobT contributes to T helper (Th) 1 polarization of the immune response. MAP CobT-treated DCs specifically induced the expansion of CD4(+)/CD8(+)CD44(high)CD62L(low) memory T cells in the mesenteric lymph node of MAP-infected mice in a TLR4-dependent manner. Our results indicate that MAP CobT is a novel DC maturation-inducing antigen that drives Th1 polarized-naive/memory T cell expansion in a TLR4-dependent cascade, suggesting that MAP CobT potentially links innate and adaptive immunity against MAP. PMID:23019321

  4. Glucose activation of islets of Langerhans up-regulates Toll-like receptor 5: possible mechanism of protection

    Weile, Christian Roar Andersen; Josefsen, Knud Elnegaard; Buschard, Karsten Stig

    2011-01-01

    binding of flagellin from pathogenic bacteria such as Salmonella and Listeria species. We have found that the expression of TLR5 is up-regulated by glucose activation of isolated islets of Langerhans, in contrast to other investigated TLRs (TLR-2, -3, -4, -6 and -9. Stimulation of islets with 10 mm...... glucose increased the levels of TLR5 mRNA 10-fold (P=0·03) and the TLR-5 protein levels twofold (P=0·04). Furthermore, the protein level of downstream signalling molecule myeloid differentiation primary response gene 88 (MyD88) increased 1·6-fold (P=0·01). Activation of TLR-5 in islets lead to a marked...

  5. The Therapeutic Potential of Toll-like Receptor 7 Stimulation in Asthma

    Drake, Matthew G.; Kaufman, Elad H.; Fryer, Allison D.; Jacoby, David B.

    2012-01-01

    Asthma is an inflammatory disorder of the airways frequently characterized by an excessive Th2 adaptive immune response. Activation of Toll-like receptor (TLR)-7, a single-stranded viral RNA receptor that is highly expressed in the airways, triggers a rapid innate immune response and favors a subsequent Th1 response. Because of this role in pulmonary immunoregulation, TLR7 has gained considerable interest as a therapeutic target in asthma. Synthetic TLR7 ligands, including the imidazoquinolin...

  6. DAT isn’t all that: cocaine reward and reinforcement requires Toll Like Receptor 4 signaling

    Northcutt, A.L.; Hutchinson, M.R.; Wang, X.; Baratta, M.V.; Hiranita, T.; Cochran, T.A.; Pomrenze, M.B.; Galer, E.L.; Kopajtic, T.A.; Li, C.M.; AMAT, J.; Larson, G.; Cooper, D. C.; Huang, Y.; O’Neill, C.E.

    2015-01-01

    The initial reinforcing properties of drugs of abuse, such as cocaine, are largely attributed to their ability to activate the mesolimbic dopamine system. Resulting increases in extracellular dopamine in the nucleus accumbens (NAc) are traditionally thought to result from cocaine’s ability to block dopamine transporters (DATs). Here we demonstrate that cocaine also interacts with the immunosurveillance receptor complex, Toll-Like Receptor 4 (TLR4), on microglial cells to initiate central inna...

  7. Maternal endotoxin-induced fetal growth restriction in rats: Fetal responses in toll-like receptor

    Banun Kusumawardani; Marsetyawan HNE Soesatyo; Djaswadi Dasuki; Widya Asmara

    2012-01-01

    Background: Porphyromonas gingivalis as a major etiology of periodontal disease can produce virulence factor, lipopolysaccharide/LPS, which is expected to play a role in the intrauterine fetal growth. Trophoblast at the maternal-fetal interface actively participates in response to infection through the expression of a family of natural immune receptors, toll-like receptor (TLR). Purpose: the aims of study were to identify endotoxin concentration in maternal blood serum of Porphyromonas gingiv...

  8. A Comparative Review of Toll-Like Receptor 4 Expression and Functionality in Different Animal Species

    Vaure, Céline; Liu, Yuanqing

    2014-01-01

    Toll-like receptors (TLRs) belong to the pattern recognition receptor (PRR) family, a key component of the innate immune system. TLRs detect invading pathogens and initiate an immediate immune response to them, followed by a long-lasting adaptive immune response. Activation of TLRs leads to the synthesis of pro-inflammatory cytokines and chemokines and the expression of co-stimulatory molecules. TLR4 specifically recognizes bacterial lipopolysaccharide, along with several other components of ...

  9. A comprehensive map of the toll-like receptor signaling network

    Oda, Kanae; Kitano, Hiroaki

    2006-01-01

    Recognition of pathogen-associated molecular signatures is critically important in proper activation of the immune system. The toll-like receptor (TLR) signaling network is responsible for innate immune response. In mammalians, there are 11 TLRs that recognize a variety of ligands from pathogens to trigger immunological responses. In this paper, we present a comprehensive map of TLRs and interleukin 1 receptor signaling networks based on papers published so far. The map illustrates the possib...

  10. Mechanisms Underlying the Anti-Inflammatory Effects of Clinacanthus nutans Lindau Extracts: Inhibition of Cytokine Production and Toll-Like Receptor-4 Activation.

    Mai, Chun W; Yap, Kok S I; Kho, Mee T; Ismail, Nor H; Yusoff, Khatijah; Shaari, Khozirah; Chin, Swee Y; Lim, Erin S H

    2016-01-01

    Clinacanthus nutans has had a long history of use in folk medicine in Malaysia and Southeast Asia; mostly in the relief of inflammatory conditions. In this study, we investigated the effects of different extracts of C. nutans upon lipopolysaccharide (LPS) induced inflammation in order to identify its mechanism of action. Extracts of leaves and stem bark of C. nutans were prepared using polar and non-polar solvents to produce four extracts, namely polar leaf extract (LP), non-polar leaf extract (LN), polar stem extract (SP), and non-polar stem extracts (SN). The extracts were standardized by determining its total phenolic and total flavonoid contents. Its anti-inflammatory effects were assessed on LPS induced nitrite release in RAW264.7 macrophages and Toll-like receptor (TLR-4) activation in TLR-4 transfected human embryonic kidney cells (HEK-Blue(TM)-hTLR4 cells). The levels of inflammatory cytokines (TNF-α, IFN-γ, IL-1β, IL-6, IL-12p40, and IL-17) in treated RAW264.7 macrophages were quantified to verify its anti-inflammatory effects. Western blotting was used to investigate the effect of the most potent extract (LP) on TLR-4 related inflammatory proteins (p65, p38, ERK, JNK, IRF3) in RAW264.7 macrophages. All four extracts produced a significant, concentration-dependent reduction in LPS-stimulated nitric oxide, LPS-induced TLR-4 activation in HEK-Blue(TM)-hTLR4 cells and LPS-stimulated cytokines production in RAW264.7 macrophages. The most potent extract, LP, also inhibited all LPS-induced TLR-4 inflammatory proteins. These results provide a basis for understanding the mechanisms underlying the previously demonstrated anti-inflammatory activity of C. nutans extracts. PMID:26869924

  11. Mechanisms underlying the anti-inflammatory effects of Clinacanthus nutans Lindau extracts: inhibition of cytokine production and Toll-like receptor-4 activation

    Chun Wai eMai

    2016-02-01

    Full Text Available Clinacanthus nutans has had a long history of use in folk medicine in Malaysia and Southeast Asia; mostly in the relief of inflammatory conditions. In this study, we investigated the effects of different extracts of C. nutans upon lipopolysaccharide (LPS induced inflammation in order to identify its mechanism of action. Extracts of leaves and stem bark of C. nutans were prepared using polar and non-polar solvents to produce four extracts, namely polar leaf extract (LP, non-polar leaf extract (LN, polar stem extract (SP and non-polar stem extracts (SN. The extracts were standardized by determining its total phenolic and total flavonoid contents. Its anti-inflammatory effects were assessed on LPS induced nitrite release in RAW264.7 macrophages and Toll-like receptor (TLR-4 activation in TLR-4 transfected human embryonic kidney cells (HEK-BlueTM-hTLR4 cells. The levels of inflammatory cytokines (TNF-α, IFN-γ, IL-1β, IL-6, IL-12p40 and IL-17 in treated RAW264.7 macrophages were quantified to verify its anti-inflammatory effects. Western blotting was used to investigate the effect of the most potent extract (LP on TLR-4 related inflammatory proteins (p65, p38, ERK, JNK, IRF3 in RAW264.7 macrophages. All four extracts produced a significant, concentration-dependent reduction in LPS-stimulated nitric oxide, LPS-induced TLR-4 activation in HEK-BlueTM-hTLR4 cells and LPS-stimulated cytokines production in RAW264.7 macrophages. The most potent extract, LP, also inhibited all LPS-induced TLR-4 inflammatory proteins. These results provide a basis for understanding the mechanisms underlying the previously demonstrated anti-inflammatory activity of C. nutans extracts.

  12. Penicillin binding proteins as danger signals: meningococcal penicillin binding protein 2 activates dendritic cells through Toll-like receptor 4.

    Marcelo Hill

    Full Text Available Neisseria meningitidis is a human pathogen responsible for life-threatening inflammatory diseases. Meningococcal penicillin-binding proteins (PBPs and particularly PBP2 are involved in bacterial resistance to β-lactams. Here we describe a novel function for PBP2 that activates human and mouse dendritic cells (DC in a time and dose-dependent manner. PBP2 induces MHC II (LOGEC50 = 4.7 µg/ml ± 0.1, CD80 (LOGEC50 = 4.88 µg/ml ± 0.15 and CD86 (LOGEC50 = 5.36 µg/ml ± 0.1. This effect was abolished when DCs were co-treated with anti-PBP2 antibodies. PBP2-treated DCs displayed enhanced immunogenic properties in vitro and in vivo. Furthermore, proteins co-purified with PBP2 showed no effect on DC maturation. We show through different in vivo and in vitro approaches that this effect is not due to endotoxin contamination. At the mechanistic level, PBP2 induces nuclear localization of p65 NF-kB of 70.7 ± 5.1% cells versus 12 ± 2.6% in untreated DCs and needs TLR4 expression to mature DCs. Immunoprecipitation and blocking experiments showed thatPBP2 binds TLR4. In conclusion, we describe a novel function of meningococcal PBP2 as a pathogen associated molecular pattern (PAMP at the host-pathogen interface that could be recognized by the immune system as a danger signal, promoting the development of immune responses.

  13. The Role of Toll Like Receptors in Pregnancy

    Elham Amirchaghmaghi

    2013-09-01

    Full Text Available For many years, the innate immunity was of less interest than the adaptive immunity because it was perceived to have secondary importance in the functionality of the immune system. During the past decades, with the advancement of knowledge about innate immune system, interest in innate immunity has grown dramatically and thus its function has been extensively studied. Innate immunity plays fundamental roles in the initiation and induction of adaptive immune responses. It consists of several cells and receptors including natural killer (NK cells, macrophages (MQs, dendritic cells (DCs and pattern recognition receptors (PRRs. Two decades ago, Toll like receptors (TLRs family was known as one of the important PRRs with unique functions especially in protection against invading pathogens. Since the female reproductive tract has access to the outside environment and has a unique interaction with different pathogens whether invading microorganisms or normal flora, allogenic sperm and semi allogenic fetus, it has an essential need for effective immune responses. It has therefore been suggested that TLRs may play important roles in the immune regulation of the female reproductive tract. In addition, it has been demonstrated that immune disturbance may be responsible for some adverse pregnancy outcomes such as preeclampsia (PE, recurrent spontaneous abortion (RSA and intrauterine growth restriction (IUGR. Our focus in this review is to show the importance of TLRs in pregnancy with emphasis on the expression of these receptors in different tissues related to pregnancy.

  14. Increased expression of Toll-like receptors 7 and 9 in myasthenia gravis thymus characterized by active Epstein-Barr virus infection.

    Cavalcante, Paola; Galbardi, Barbara; Franzi, Sara; Marcuzzo, Stefania; Barzago, Claudia; Bonanno, Silvia; Camera, Giorgia; Maggi, Lorenzo; Kapetis, Dimos; Andreetta, Francesca; Biasiucci, Amelia; Motta, Teresio; Giardina, Carmelo; Antozzi, Carlo; Baggi, Fulvio; Mantegazza, Renato; Bernasconi, Pia

    2016-04-01

    Considerable data implicate the thymus as the main site of autosensitization to the acetylcholine receptor in myasthenia gravis (MG), a B-cell-mediated autoimmune disease affecting the neuromuscular junction. We recently demonstrated an active Epstein-Barr virus (EBV) infection in the thymus of MG patients, suggesting that EBV might contribute to the onset or maintenance of the autoimmune response within MG thymus, because of its ability to activate and immortalize autoreactive B cells. EBV has been reported to elicit and modulate Toll-like receptor (TLR) 7- and TLR9-mediated innate immune responses, which are known to favor B-cell dysfunction and autoimmunity. Aim of this study was to investigate whether EBV infection is associated with altered expression of TLR7 and TLR9 in MG thymus. By real-time PCR, we found that TLR7 and TLR9 mRNA levels were significantly higher in EBV-positive MG compared to EBV-negative normal thymuses. By confocal microscopy, high expression levels of TLR7 and TLR9 proteins were observed in B cells and plasma cells of MG thymic germinal centers (GCs) and lymphoid infiltrates, where the two receptors co-localized with EBV antigens. An increased frequency of Ki67-positive proliferating B cells was found in MG thymuses, where we also detected proliferating cells expressing TLR7, TLR9 and EBV antigens, thus supporting the idea that EBV-associated TLR7/9 signaling may promote abnormal B-cell activation and proliferation. Along with B cells and plasma cells, thymic epithelium, plasmacytoid dendritic cells and macrophages exhibited enhanced TLR7 and TLR9 expression in MG thymus; TLR7 was also increased in thymic myeloid dendritic cells and its transcriptional levels positively correlated with those of interferon (IFN)-β. We suggested that TLR7/9 signaling may be involved in antiviral type I IFN production and long-term inflammation in EBV-infected MG thymuses. Our overall findings indicate that EBV-driven TLR7- and TLR9-mediated innate immune

  15. Toll-like Receptors and Renal Bacterial Infections

    Alain Vandewalle

    2008-06-01

    Full Text Available Urinary tract infection and pyelonephritis are mainly dueto uropathogenic Escherichia coli (UPEC, and are commoninfectious diseases that constitute a significant cause of morbidity and mortality in humans. They are also the most frequent infectious complications in renal transplant patients, andcan impair long-term renal graft function and outcome. UPECmay invade the kidneys via the systemic circulation or by localretrograde infection. They induce the proinflammatory mediators, which are intended to defend the host and clear bacteriafrom the kidneys. The Toll-like receptors (TLRs play a keyrole in the recognition of bacterial components and in inducingthe inflammatory response that is mediated by various intracellular signaling pathways. To date, 13 TLRs have been identified in mammals. Recent studies have provided evidence suggesting that renal tubule epithelial cells express most of theTLRs initially identified in bone marrow-derived cells. Murine renal tubule cells expressTLR1, 2, 3, 4, 6, and 11. TLR4, which recognizes lipopolysaccharide (LPS, the main constituent of Gram-negative bacteria, plays a key role in inducing the inflammatory responseselicited by UPEC. This review will consider some aspects of TLR function in the kidney,particularly in the renal tubule epithelial cells, and the role of these receptors in enabling thebody to cope with urinary tract infections and pyelonephritis caused by UPECs.

  16. Toll-Like Receptor Pathways in Autoimmune Diseases.

    Chen, Ji-Qing; Szodoray, Peter; Zeher, Margit

    2016-02-01

    Autoimmune diseases are a family of chronic systemic inflammatory disorders, characterized by the dysregulation of the immune system which finally results in the break of tolerance to self-antigen. Several studies suggest that Toll-like receptors (TLRs) play an essential role in the pathogenesis of autoimmune diseases. TLRs belong to the family of pattern recognition receptors (PRRs) that recognize a wide range of pathogen-associated molecular patterns (PAMPs). TLRs are type I transmembrane proteins and located on various cellular membranes. Two main groups have been classified based on their location; the extracelluar group referred to the ones located on the plasma membrane while the intracellular group all located in endosomal compartments responsible for the recognition of nucleic acids. They are released by the host cells and trigger various intracellular pathways which results in the production of proinflammatory cytokines, chemokines, as well as the expression of co-stimulatory molecules to protect against invading microorganisms. In particular, TLR pathway-associated proteins, such as IRAK, TRAF, and SOCS, are often dysregulated in this group of diseases. TLR-associated gene expression profile analysis together with single nucleotide polymorphism (SNP) assessment could be important to explain the pathomechanism driving autoimmune diseases. In this review, we summarize recent findings on TLR pathway regulation in various autoimmune diseases, including Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), multiple sclerosis (MS), rheumatoid arthritis (RA), systemic sclerosis (SSc), and psoriasis. PMID:25687121

  17. Gain-of-function mutations in the Toll-like Receptor pathway: TPL2-mediated ERK1/ERK2 MAPK activation, a path to tumorigenesis in lymphoid neoplasms?

    Simon eRousseau

    2016-05-01

    Full Text Available Lymphoid neoplasms form a family of cancers affecting B-cells, T-cells and NK cells. The Toll-Like Receptor (TLR signalling adapter molecule MYD88 is the most frequently mutated gene in these neoplasms. This signalling adaptor relays signals from TLRs to downstream effector pathways such as the Nuclear Factor kappa B (NFB and Mitogen Activated Protein Kinase (MAPK pathways to regulate innate immune responses (Kawai and Akira, 2010. Gain-of-function mutations such as MYD88[L265P] activate downstream signalling pathways in absence of cognate ligands for TLRs, resulting in increased cellular proliferation and survival. This article reports an analysis of non-synonymous somatic mutations found in the TLR signaling network in lymphoid neoplasms. In accordance with previous reports, mutations map to MYD88 pro-inflammatory signaling and not TRIF-mediated Type I IFN production. Interestingly, the analysis of somatic mutations found downstream of the core TLR-signaling network uncovered a strong association with the ERK1/2 MAPK cascade. In support of this analysis, heterologous expression of MYD88[L265P] in HEK 293 cells led to ERK1/2 MAPK phosphorylation in addition to NFB activation. Moreover, this activation is dependent on the protein kinase Tumour Promoting Locus-2 (TPL-2, activated downstream of the IKK complex. Activation of ERK1/2 would then lead to activation, amongst others, of MYC and hnRNP A1, two proteins previously shown to contribute to tumour formation in lymphoid neoplasms. Taken together, this analysis suggests that TLR-mediated tumorigenesis occurs via the TPL2-mediated ERK1/2 activation. Therefore, the hypothesis proposed is that inhibition of ERK1/2 MAPK activation would prevent tumour growth downstream of MYD88[L265]. It will be interesting to test whether pharmacological inhibitors of this pathway show efficacy in primary tumour cells derived from hematologic malignancies such as Waldenstrom’s Macroglobulinemia, where the

  18. Activation of human B cells by the agonist CD40 antibody CP-870,893 and augmentation with simultaneous toll-like receptor 9 stimulation

    Rüter Jens

    2009-11-01

    Full Text Available Abstract Background CD40 activation of antigen presenting cells (APC such as dendritic cells (DC and B cells plays an important role in immunological licensing of T cell immunity. Agonist CD40 antibodies have been previously shown in murine models to activate APC and enhance tumor immunity; in humans, CD40-activated DC and B cells induce tumor-specific T cells in vitro. Although clinical translation of these findings for patients with cancer has been previously limited due to the lack of a suitable and available drug, promising clinical results are now emerging from phase I studies of the agonist CD40 monoclonal antibody CP-870,893. The most prominent pharmacodynamic effect of CP-870,893 infusion is peripheral B cell modulation, but direct evidence of CP-870,893-mediated B cell activation and the potential impact on T cell reactivity has not been reported, despite increasing evidence that B cells, like DC, regulate cellular immunity. Methods Purified total CD19+ B cells, CD19+ CD27+ memory, or CD19+ CD27neg subsets from peripheral blood were stimulated in vitro with CP-870,893, in the presence or absence of the toll like receptor 9 (TLR9 ligand CpG oligodeoxynucleotide (ODN. B cell surface molecule expression and cytokine secretion were evaluated using flow cytometry. Activated B cells were used as stimulators in mixed lymphocyte reactions to evaluate their ability to induce allogeneic T cell responses. Results Incubation with CP-870,893 activated B cells, including both memory and naïve B cells, as demonstrated by upregulation of CD86, CD70, CD40, and MHC class I and II. CP-870,893-activated B cells induced T cell proliferation and T cell secretion of effector cytokines including IFN-gamma and IL-2. These effects were increased by TLR9 co-stimulation via a CpG ODN identical in sequence to a well-studied clinical grade reagent. Conclusion The CD40 mAb CP-870,893 activates both memory and naïve B cells and triggers their T cell stimulatory

  19. Gain-of-Function Mutations in the Toll-Like Receptor Pathway: TPL2-Mediated ERK1/ERK2 MAPK Activation, a Path to Tumorigenesis in Lymphoid Neoplasms?

    Rousseau, Simon; Martel, Guy

    2016-01-01

    Lymphoid neoplasms form a family of cancers affecting B-cells, T-cells, and NK cells. The Toll-Like Receptor (TLR) signaling adapter molecule MYD88 is the most frequently mutated gene in these neoplasms. This signaling adaptor relays signals from TLRs to downstream effector pathways such as the Nuclear Factor kappa B (NFκB) and Mitogen Activated Protein Kinase (MAPK) pathways to regulate innate immune responses. Gain-of-function mutations such as MYD88[L265P] activate downstream signaling pathways in absence of cognate ligands for TLRs, resulting in increased cellular proliferation and survival. This article reports an analysis of non-synonymous somatic mutations found in the TLR signaling network in lymphoid neoplasms. In accordance with previous reports, mutations map to MYD88 pro-inflammatory signaling and not TRIF-mediated Type I IFN production. Interestingly, the analysis of somatic mutations found downstream of the core TLR-signaling network uncovered a strong association with the ERK1/2 MAPK cascade. In support of this analysis, heterologous expression of MYD88[L265P] in HEK293 cells led to ERK1/2 MAPK phosphorylation in addition to NFκB activation. Moreover, this activation is dependent on the protein kinase Tumor Promoting Locus 2 (TPL2), activated downstream of the IKK complex. Activation of ERK1/2 would then lead to activation, amongst others, of MYC and hnRNPA1, two proteins previously shown to contribute to tumor formation in lymphoid neoplasms. Taken together, this analysis suggests that TLR-mediated ERK1/2 activation via TPL2 may be a novel path to tumorigenesis. Therefore, the hypothesis proposed is that inhibition of ERK1/2 MAPK activation would prevent tumor growth downstream of MYD88[L265]. It will be interesting to test whether pharmacological inhibitors of this pathway show efficacy in primary tumor cells derived from hematologic malignancies such as Waldenstrom's Macroglobulinemia, where the majority of the cells carry the MYD88[L265P

  20. Exploitation of the Toll-like receptor system in cancer: a doubled-edged sword?

    Killeen, S D

    2012-02-03

    The toll-like receptor (TLR) system constitutes a pylogenetically ancient, evolutionary conserved, archetypal pattern recognition system, which underpins pathogen recognition by and activation of the immune system. Toll-like receptor agonists have long been used as immunoadjuvants in anti cancer immunotherapy. However, TLRs are increasingly implicated in human disease pathogenesis and an expanding body of both clinical and experimental evidence suggests that the neoplastic process may subvert TLR signalling pathways to advance cancer progression. Recent discoveries in the TLR system open a multitude of potential therapeutic avenues. Extrapolation of such TLR system manipulations to a clinical oncological setting demands care to prevent potentially deleterious activation of TLR-mediated survival pathways. Thus, the TLR system is a double-edge sword, which needs to be carefully wielded in the setting of neoplastic disease.

  1. Role of toll-like receptor 2 and toll-like receptor 4 in post-ischemic coronary endothelial dysfunction in mice

    J.FAVRE; P.MUSETTE; JPHENRY; C.THUILLEZ; V.RICHARD

    2004-01-01

    AIM: A growing body of evidence suggests a role of the toll-like receptors (TLR) in inflammatory processes. In addition to LPS,TLR are activated by many endogenous ligands such as heat shock proteins and oxygeil-derived free radicals which are both produced during cardiac ischemia-reperfusion (I/R). Among TLR,TLR-2 and TLR-4 are expressed in endothelial and myocardial cells and appear to regulate neutrophil-endothelial interactions.Since neutrophil adhesion is a critical event in endothelial injury

  2. Substance P primes lipoteichoic acid- and Pam3CysSerLys4-mediated activation of human mast cells by up-regulating Toll-like receptor 2.

    Tancowny, Brian P; Karpov, Victor; Schleimer, Robert P; Kulka, Marianna

    2010-10-01

    Substance P (SP) is a neuropeptide with neuroimmunoregulatory activity that may play a role in susceptibility to infection. Human mast cells, which are important in innate immune responses, were analysed for their responses to pathogen-associated molecules via Toll-like receptors (TLRs) in the presence of SP. Human cultured mast cells (LAD2) were activated by SP and TLR ligands including lipopolysaccharide (LPS), Pam3CysSerLys4 (Pam3CSK4) and lipoteichoic acid (LTA), and mast cell leukotriene and chemokine production was assessed by enzyme-linked immunosorbent assay (ELISA) and gene expression by quantitative PCR (qPCR). Mast cell degranulation was determined using a β-hexosaminidase (β-hex) assay. SP treatment of LAD2 up-regulated mRNA for TLR2, TLR4, TLR8 and TLR9 while anti-immunoglobulin E (IgE) stimulation up-regulated expression of TLR4 only. Flow cytometry and western blot confirmed up-regulation of TLR2 and TLR8. Pretreatment of LAD2 with SP followed by stimulation with Pam3CSK4 or LTA increased production of leukotriene C4 (LTC(4) ) and interleukin (IL)-8 compared with treatment with Pam3CSK4 or LTA alone (>2-fold; P<0·01). SP alone activated 5-lipoxygenase (5-LO) nuclear translocation but also augmented Pam3CSK4 and LTA-mediated 5-LO translocation. Pam3CSK4, LPS and LTA did not induce LAD2 degranulation. SP primed LTA and Pam3CSK4-mediated activation of JNK, p38 and extracellular-signal-regulated kinase (ERK) and activated the nuclear translocation of c-Jun, nuclear factor (NF)-κB, activating transcription factor 2 (ATF-2) and cyclic-AMP-responsive element binding protein (CREB) transcription factors. Pretreatment with SP followed by LTA stimulation synergistically induced production of chemokine (C-X-C motif) ligand 8 (CXCL8)/IL-8, chemokine (C-C motif) ligand 2 (CCL2)/monocyte chemotactic protein 1 (MCP-1), tumour necrosis factor (TNF) and IL-6 protein. SP primes TLR2-mediated activation of human mast cells by up-regulating TLR expression and

  3. Therapeutic Targeting of Toll-Like Receptors for Infectious and Inflammatory Diseases and Cancer

    O'Neill, Luke A. J.; Bryant, Clare E.; Doyle, Sarah L

    2009-01-01

    Since first being described in the fruit fly Drosophila melanogaster, Toll-like receptors (TLRs) have proven to be of great interest to immunologists and investigators interested in the molecular basis to inflammation. They recognize pathogen-derived factors and also products of inflamed tissue, and trigger signaling pathways that lead to activation of transcription factors such as nuclear factor-κB and the interferon regulatory...

  4. Bupleurum Polysaccharides Attenuates Lipopolysaccharide-Induced Inflammation via Modulating Toll-Like Receptor 4 Signaling

    Wu, Jian; Zhang, Yun-Yi; Guo, Li; LI Hong; Chen, Dao-Feng

    2013-01-01

    Background Bupleurum polysaccharides (BPs), isolated from Bupleurum smithii var. parvifolium, possesses immunomodulatory activity, particularly on inflammation. Bacterial endotoxin lipopolysaccharide (LPS) triggers innate immune responses through Toll-like receptor 4 (TLR4) on host cell membrane. The present study was performed to evaluate whether the therapeutic efficacy of BPs on suppression of LPS’s pathogenecity could be associated with the modulating of TLR4 signaling pathway. Methodolog...

  5. Alcohol,nutrition and liver cancer:Role of Toll-like receptor signaling

    Samuel; W; French; Joan; Oliva; Barbara; A; French; Fawzia; Bardag-Gorce

    2010-01-01

    This article reviews the evidence that ties the development of hepatocellular carcinoma (HCC) to the natural immune pro-inflammatory response to chronic liver disease, with a focus on the role of Toll-like receptor (TLR) signaling as the mechanism of liver stem cell/progenitor transformation to HCC. Two exemplary models of this phenomenon are reviewed in detail. One model applies chronic ethanol/lipopolysaccharide feeding to the activated TLR4 signaling pathway. The other applies chronic feeding of a carcin...

  6. Human herpesvirus 6 infection impairs Toll-like receptor signaling

    Ochi Toshiki

    2010-05-01

    Full Text Available Abstract Human herpesvirus 6 (HHV-6 has a tropism for immunocompetent cells, including T lymphocytes, monocytes/macrophages, and dendritic cells (DCs suggesting that HHV-6 infection affects the immunosurveillance system. Toll-like receptor (TLR system plays an important role in innate immunity against various pathogens. In the present study, we investigated the effect of HHV-6 infection on the expression and intracellular signaling of TLRs in DCs. Although expression levels of TLRs were not decreased or slightly elevated following HHV-6 infection, the amounts of cytokines produced following stimulation with ligands for TLRs appeared to be dramatically decreased in HHV-6-infected DCs as compared to mock-infected DCs. Similarly, phosphorylation levels of TAK-1, IκB kinase, and IκB-α following stimulation of HHV-6-infected DCs with lipopolysaccharide, which is the ligand for TLR4, appeared to be decreased. These data show that HHV-6 impairs intracellular signaling through TLRs indicating the novel mechanism of HHV-6-mediated immunomodulation.

  7. Toll-like receptor 4 mediates microglial activation and production of inflammatory mediators in neonatal rat brain following hypoxia: role of TLR4 in hypoxic microglia

    Yao Linli

    2013-02-01

    Full Text Available Abstract Background Hypoxia induces microglial activation which causes damage to the developing brain. Microglia derived inflammatory mediators may contribute to this process. Toll-like receptor 4 (TLR4 has been reported to induce microglial activation and cytokines production in brain injuries; however, its role in hypoxic injury remains uncertain. We investigate here TLR4 expression and its roles in neuroinflammation in neonatal rats following hypoxic injury. Methods One day old Wistar rats were subjected to hypoxia for 2 h. Primary cultured microglia and BV-2 cells were subjected to hypoxia for different durations. TLR4 expression in microglia was determined by RT-PCR, western blot and immunofluorescence staining. Small interfering RNA (siRNA transfection and antibody neutralization were employed to downregulate TLR4 in BV-2 and primary culture. mRNA and protein expression of tumor necrosis factor-alpha (TNF-α, interleukin-1 beta (IL-1β and inducible nitric oxide synthase (iNOS was assessed. Reactive oxygen species (ROS, nitric oxide (NO and NF-κB levels were determined by flow cytometry, colorimetric and ELISA assays respectively. Hypoxia-inducible factor-1 alpha (HIF-1α mRNA and protein expression was quantified and where necessary, the protein expression was depleted by antibody neutralization. In vivo inhibition of TLR4 with CLI-095 injection was carried out followed by investigation of inflammatory mediators expression via double immunofluorescence staining. Results TLR4 immunofluorescence and protein expression in the corpus callosum and cerebellum in neonatal microglia were markedly enhanced post-hypoxia. In vitro, TLR4 protein expression was significantly increased in both primary microglia and BV-2 cells post-hypoxia. TLR4 neutralization in primary cultured microglia attenuated the hypoxia-induced expression of TNF-α, IL-1β and iNOS. siRNA knockdown of TLR4 reduced hypoxia-induced upregulation of TNF-α, IL-1β, iNOS, ROS and

  8. Calpain Activity and Toll-Like Receptor 4 Expression in Platelet Regulate Haemostatic Situation in Patients Undergoing Cardiac Surgery and Coagulation in Mice

    Jui-Chi Tsai

    2014-01-01

    Full Text Available Human platelets express Toll-like receptors (TLR 4. However, the mechanism by which TLR4 directly affects platelet aggregation and blood coagulation remains to be explored. Therefore, in this study, we evaluated the platelet TLR4 expression in patients who underwent CABG surgery; we explored the correlation between platelet TLR4 expression and the early outcomes in hospital of patients. Additionally, C57BL/6 and C57BL/6-TlrLPS−/− mice were used to explore the roles of platelet TLR4 in coagulation by platelet aggregometry and rotation thromboelastometry. In conclusion, our results highlight the important roles of TLR4 in blood coagulation and platelet function. Of clinical relevance, we also explored novel roles for platelet TLR4 that are associated with early outcomes in cardiac surgery.

  9. A species-specific activation of Toll-like receptor signaling in bovine and sheep bronchial epithelial cells triggered by Mycobacterial infections.

    Ma, Yan; Han, Fei; Liang, Jinping; Yang, Jiali; Shi, Juan; Xue, Jing; Yang, Li; Li, Yong; Luo, Meihui; Wang, Yujiong; Wei, Jun; Liu, Xiaoming

    2016-03-01

    Pulmonary tuberculosis caused by a Mycobacterium infection remains a major public health problem in most part of the world, in part owing to the transmission of its pathogens between hosts including human, domestic and wild animals. To date, molecular mechanisms of the pathogenesis of TB are still incompletely understood. In addition to alveolar macrophages, airway epithelial cells have also been recently recognized as main targets for Mycobacteria infections. In an effort to understand the pathogen-host interaction between Mycobacteria and airway epithelial cells in domestic animals, in present study, we investigated the Toll-like receptor (TLR) signaling in bovine and sheep airway epithelial cells in response to an infection of Mycobacterium tuberculosis avirulent H37Ra stain or Mycobacterium bovis BCG vaccine strain, using primary air-liquid interface (ALI) bronchial epithelial culture models. Our results revealed a host and pathogen species-specific TLR-mediated recognition of pathogen-associated molecular patterns (PAMPs), induction and activation of TLR signaling pathways, and substantial induction of inflammatory response in bronchial epithelial cells in response to Mycobacteria infections between these two species. Interestingly, the activation TLR signaling in bovine bronchial epithelial cells induced by Mycobacteria infection was mainly through a myeloid differentiation factor 88 (MyD88)-independent TLR signaling pathway, while both MyD88-dependent and independent TLR signaling cascades could be induced in sheep epithelial cells. Equally noteworthy, a BCG infection was able to induce both MyD88-dependent and independent signaling in sheep and bovine airway epithelial cells, but more robust inflammatory responses were induced in sheep epithelial cells relative to the bovines; whereas an H37Ra infection displayed an ability to mainly trigger a MyD88-independent TLR signaling cascade in these two host species, and induce a more extent expression of

  10. Penehyclidine ameliorates acute lung injury by inhibiting Toll-like receptor 2/4 expression and nuclear factor-κB activation

    WANG, NA; SU, YUE; CHE, XIANG-MING; ZHENG, HUI; SHI, ZHI-GUO

    2016-01-01

    The aim of the present study was to investigate the effect of penehyclidine (PHC) on endotoxin-induced acute lung injury (ALI), as well as to examine the mechanism underlying this effect. A total of 60 rats were randomly divided into five groups, including the control (saline), LPS and three LPS + PHC groups. ALI was induced in the rats by injection of 8 mg lipopolysaccharide (LPS)/kg body weight. The rats were then treated with or without PHC at 0.3, 1 or 3 mg/kg body weight 1 min following LPS injection. After 6 h, serum levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 were determined by ELISA. In addition, the mRNA expression levels of toll-like receptor (TLR)2 and TLR4 were examined by reverse transcription-quantitative polymerase chain reaction in the lung tissue samples, and nuclear factor (NF)-κB p65 protein expression levels were examined by western blot analysis. The results demonstrated that lung injury was ameliorated by treatment with PHC (1 and 3 mg/kg body weight) as compared with treatment with LPS alone. Injection of LPS significantly increased the mRNA expression levels of TLR2 and TLR4, as well as the protein expression levels of NF-κB p65 in the lung tissue samples. Serum levels of TNF-α and IL-6 were also upregulated by LPS injection. Treatment of the rats with PHC following LPS injection suppressed the LPS-induced increase in TLR2/4 mRNA and NF-κB p65 protein expression levels. PHC also inhibited the increase in TNF-α and IL-6 serum levels. In addition, PHC reduced LPS-induced ALI and decreased the serum levels of TNF-α and IL-6, possibly by downregulating TLR2/4 mRNA expression and inhibiting NF-κB activity, and consequently alleviating the inflammatory response. PMID:27168812

  11. Anti-inflammatory activity of Odina wodier Roxb, an Indian folk remedy, through inhibition of toll-like receptor 4 signaling pathway.

    Durbadal Ojha

    Full Text Available Inflammation is part of self-limiting non-specific immune response, which occurs during bodily injury. In some disorders the inflammatory process becomes continuous, leading to the development of chronic inflammatory diseases including cardiovascular diseases, diabetes, cancer etc. Several Indian tribes used the bark of Odina wodier (OWB for treating inflammatory disorders. Thus, we have evaluated the immunotherapeutic potential of OWB methanol extract and its major constituent chlorogenic acid (CA, using three popular in vivo antiinflammatory models: Carrageenan- and Dextran-induced paw edema, Cotton pellet granuloma, and Acetic acid-induced vascular permeability. To elucidate the possible anti-inflammatory mechanism of action we determine the level of major inflammatory mediators (NO, iNOS, COX-2-dependent prostaglandin E2 or PGE2, and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-12. Further, we determine the toll-like receptor 4 (TLR4, Myeloid differentiation primary response gene 88 (MyD88, c-Jun N-terminal kinases (JNK, nuclear factor kappa-B cells (NF-κB, and NF-kB inhibitor alpha (IK-Bα by protein and mRNA expression, and Western blot analysis in drug treated LPS-induced murine macrophage model. Moreover, we determined the acute and sub-acute toxicity of OWB extract in BALB/c mice. Our study demonstrated a significant anti-inflammatory activity of OWB extract and CA along with the inhibition of TNF-α, IL-1β, IL-6 and IL-12 expressions. Further, the expression of TLR4, NF-κBp65, MyD88, iNOS and COX-2 molecules were reduced in drug-treated groups, but not in the LPS-stimulated untreated or control groups, Thus, our results collectively indicated that the OWB extract and CA can efficiently inhibit inflammation through the down regulation of TLR4/MyD88/NF-kB signaling pathway.

  12. DMPD: Translational mini-review series on Toll-like receptors: recent advances inunderstanding the role of Toll-like receptors in anti-viral immunity. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17223961 Translational mini-review series on Toll-like receptors: recent advances i...147(2):217-26. (.png) (.svg) (.html) (.csml) Show Translational mini-review series on Toll-like receptors: recent advances...nity. PubmedID 17223961 Title Translational mini-review series on Toll-like receptors: recent advances inund

  13. Up-regulation of Toll-like receptors 2, 3 and 4 in allergic rhinitis

    Uddman Rolf

    2005-09-01

    Full Text Available Abstract Background Toll-like receptors enable the host to recognize a large number of pathogen-associated molecular patterns such as bacterial lipopolysaccharide, viral RNA, CpG-containing DNA and flagellin. Toll-like receptors have also been shown to play a pivotal role in both innate and adaptive immune responses. The role of Toll-like receptors as a primary part of our microbe defense system has been shown in several studies, but their possible function as mediators in allergy and asthma remains to be established. The present study was designed to examine the expression of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with intermittent allergic rhinitis, focusing on changes induced by exposure to pollen. Methods 27 healthy controls and 42 patients with seasonal allergic rhinitis volunteered for the study. Nasal biopsies were obtained before and during pollen season as well as before and after allergen challenge. The seasonal material was used for mRNA quantification of Toll-like receptors 2, 3 and 4 with real-time polymerase chain reaction, whereas specimens achieved in conjunction with allergen challenge were used for immunohistochemical localization and quantification of corresponding proteins. Results mRNA and protein representing Toll-like receptors 2, 3 and 4 could be demonstrated in all specimens. An increase in protein expression for all three receptors could be seen following allergen challenge, whereas a significant increase of mRNA only could be obtained for Toll-like receptor 3 during pollen season. Conclusion The up-regulation of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with symptomatic allergic rhinitis supports the idea of a role for Toll-like receptors in allergic airway inflammation.

  14. Toll-like receptor 2 agonists inhibit human fibrocyte differentiation

    Maharjan Anu S

    2010-11-01

    Full Text Available Abstract Background In healing wounds, some monocytes enter the wound and differentiate into fibroblast-like cells called fibrocytes. Since Toll-like receptors (TLRs are present on monocytes, and pathogens that can infect a wound have and/or release TLR agonists, we examined whether TLR agonists affect fibrocyte differentiation. Results When human peripheral blood mononuclear cells (PBMCs were cultured with TLR3, TLR4, TLR5, TLR7, TLR8 or TLR9 agonists, there was no significant effect on fibrocyte differentiation, even though enhanced extracellular tumor necrosis factor (TNF-α accumulation and/or increased cell surface CD86 or major histocompatibility complex (MHC class II levels were observed. However, all TLR2 agonists tested inhibited fibrocyte differentiation without any significant effect on cell survival. Adding TLR2 agonists to purified monocytes had no effect on fibrocyte differentiation. However, some TLR2 agonists caused PBMCs to secrete a factor that inhibits the differentiation of purified monocytes into fibrocytes. This factor is not interferon (IFN-α, IFN-γ, interleukin (IL-12, aggregated immunoglobulin G (IgG or serum amyloid P (SAP, factors known to inhibit fibrocyte differentiation. TLR2 agonist-treated PBMCs secrete low levels of IL-6, TNF-α, IFN-γ, granulocyte colony-stimulating factor and tumor growth factor β1, but combinations of these factors had no effect on fibrocyte differentiation from purified monocytes. Conclusions Our results indicate that TLR2 agonists indirectly inhibit fibrocyte differentiation and that, for some TLR2 agonists, this inhibition involves other cell types in the PBMC population secreting an unknown factor that inhibits fibrocyte differentiation. Together, these data suggest that the presence of some bacterial signals can inhibit fibrocyte differentiation and may thus slow wound closure.

  15. Toll-like receptor polymorphisms in malaria-endemic populations

    Zimmerman Peter A

    2009-03-01

    Full Text Available Abstract Background Toll-like receptors (TLR and related downstream signaling pathways of innate immunity have been implicated in the pathogenesis of Plasmodium falciparum malaria. Because of their potential role in malaria pathogenesis, polymorphisms in these genes may be under selective pressure in populations where this infectious disease is endemic. Methods A post-PCR Ligation Detection Reaction-Fluorescent Microsphere Assay (LDR-FMA was developed to determine the frequencies of TLR2, TLR4, TLR9, MyD88-Adaptor Like Protein (MAL single nucleotide polymorphisms (SNPs, and TLR2 length polymorphisms in 170 residents of two regions of Kenya where malaria transmission is stable and high (holoendemic or episodic and low, 346 residents of a malaria holoendemic region of Papua New Guinea, and 261 residents of North America of self-identified ethnicity. Results The difference in historical malaria exposure between the two Kenyan sites has significantly increased the frequency of malaria protective alleles glucose-6-phoshpate dehydrogenase (G6PD and Hemoglobin S (HbS in the holoendemic site compared to the episodic transmission site. However, this study detected no such difference in the TLR2, TLR4, TLR9, and MAL allele frequencies between the two study sites. All polymorphisms were in Hardy Weinberg Equilibrium in the Kenyan and Papua New Guinean populations. TLR9 SNPs and length polymorphisms within the TLR2 5' untranslated region were the only mutant alleles present at a frequency greater than 10% in all populations. Conclusion Similar frequencies of TLR2, TLR4, TLR9, and MAL genetic polymorphisms in populations with different histories of malaria exposure suggest that these innate immune pathways have not been under strong selective pressure by malaria. Genotype frequencies are consistent with Hardy-Weinberg Equilibrium and the Neutral Theory, suggesting that genetic drift has influenced allele frequencies to a greater extent than selective

  16. DMPD: Toll-like receptors: paving the path to T cell-driven autoimmunity? [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17888644 Toll-like receptors: paving the path to T cell-driven autoimmunity? Marsla... Toll-like receptors: paving the path to T cell-driven autoimmunity? PubmedID 17888644 Title Toll-like recep...tors: paving the path to T cell-driven autoimmunity? Authors Marsland BJ, Kopf M.

  17. DMPD: Toll-like receptors are key participants in innate immune responses. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 18064347 Toll-like receptors are key participants in innate immune responses. Aranc...Epub 2007 Nov 21. (.png) (.svg) (.html) (.csml) Show Toll-like receptors are key participants in innate immune response...s. PubmedID 18064347 Title Toll-like receptors are key participants in innate immune response

  18. DMPD: Innate immunity and toll-like receptors: clinical implications of basic scienceresearch. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15069387 Innate immunity and toll-like receptors: clinical implications of basic sc...te immunity and toll-like receptors: clinical implications of basic scienceresearch. PubmedID 15069387 Title... Innate immunity and toll-like receptors: clinical implications of basic sciencer

  19. DMPD: Toll-like receptors: novel pharmacological targets for the treatment ofneurological diseases. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17974478 Toll-like receptors: novel pharmacological targets for the treatment ofneu...png) (.svg) (.html) (.csml) Show Toll-like receptors: novel pharmacological targets for the treatment ofneur...ological diseases. PubmedID 17974478 Title Toll-like receptors: novel pharmacological targets for the trea...tment ofneurological diseases. Authors Marsh BJ, Stenzel-Poore MP. Publication Curr

  20. Toll-like receptors are potential therapeutic targets in rheumatoid arthritis

    Siamak; Sandoghchian; Shotorbani

    2011-01-01

    Toll-like receptors (TLRs) are found on the membranes of pattern recognition receptors and not only play important roles in activating immune responses but are also involved in the pathogenesis of inflammatory disease, injury and cancer. Furthermore, TLRs are also able to recognize endogenous alarmins released by damaged tissue and necrosis and/or apoptotic cells and are present in numerous autoimmune diseases. Therefore, the release of endogenous TLR ligands plays an important role in initiating and driving inflammatory diseases. Increasing data suggest a role for TLR signaling in rheumatoid arthritis, which is an autoimmune disease. Although their involvement is not comprehensively understood, the TLRs signaling transducers may provide potential therapeutic targets.

  1. Ligands, cell-based models, and readouts required for Toll-like receptor action.

    Dellacasagrande, Jerome

    2012-02-01

    This chapter details the tools that are available to study Toll-like receptor (TLR) biology in vitro. This includes ligands, host cells, and readouts. The use of modified TLRs to circumvent some technical problems is also discussed.

  2. Toll-like Receptor 1 Polymorphisms Affect Innate Immune Responses and Outcomes in Sepsis

    Wurfel, Mark M.; Gordon, Anthony C.; Holden, Tarah D.; Radella, Frank; Strout, Jeanna; Kajikawa, Osamu; Ruzinski, John T.; Rona, Gail; Black, R. Anthony; Stratton, Seth; Jarvik, Gail P.; Hajjar, Adeline M.; Nickerson, Deborah A.; Rieder, Mark; Sevransky, Jonathan

    2008-01-01

    Rationale: Polymorphisms affecting Toll-like receptor (TLR)–mediated responses could predispose to excessive inflammation during an infection and contribute to an increased risk for poor outcomes in patients with sepsis.

  3. Anti-inflammatory effects of cordycepin in lipopolysaccharide-stimulated RAW 264.7 macrophages through Toll-like receptor 4-mediated suppression of mitogen-activated protein kinases and NF-κB signaling pathways

    Choi YH

    2014-10-01

    Full Text Available Yung Hyun Choi,1,2 Gi-Young Kim,3 Hye Hyeon Lee4 1Department of Biochemistry, Dongeui University College of Korean Medicine, Busan, 2Anti-Aging Research Center and Blue-Bio Industry RIC, Dongeui University, Busan, 3Laboratory of Immunobiology, Department of Marine Life Sciences, Jeju National University, Jeju, 4Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea Abstract: Cordycepin is the main functional component of the Cordyceps species, which has been widely used in traditional Oriental medicine. This compound possesses many pharmacological properties, such as an ability to enhance immune function, as well as antioxidant, antiaging, and anticancer effects. In the present study, we investigated the anti-inflammatory effects of cordycepin using a murine macrophage RAW 264.7 cell model. Our data demonstrated that cordycepin suppressed production of proinflammatory mediators such as nitric oxide (NO and prostaglandin E2 by inhibiting inducible NO synthase and cyclooxygenase-2 gene expression. Cordycepin also inhibited the release of proinflammatory cytokines, including tumor necrosis factor-alpha and interleukin-1-beta, through downregulation of respective mRNA expression. In addition, pretreatment with cordycepin significantly inhibited lipopolysaccharide (LPS-induced phosphorylation of mitogen-activating protein kinases and attenuated nuclear translocation of NF-κB by LPS, which was associated with abrogation of inhibitor kappa B-alpha degradation. Furthermore, cordycepin potently inhibited the binding of LPS to macrophages and LPS-induced Toll-like receptor 4 and myeloid differentiation factor 88 expression. Taken together, the results suggest that the inhibitory effects of cordycepin on LPS-stimulated inflammatory responses in RAW 264.7 macrophages are associated with suppression of mitogen-activating protein kinases and activation of NF-κB by inhibition of the Toll-like receptor 4 signaling pathway. Keywords

  4. DMPD: Signal transduction by the lipopolysaccharide receptor, Toll-like receptor-4. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15379975 Signal transduction by the lipopolysaccharide receptor, Toll-like receptor...-4. Palsson-McDermott EM, O'Neill LA. Immunology. 2004 Oct;113(2):153-62. (.png) (.svg) (.html) (.csml) Show Signal... transduction by the lipopolysaccharide receptor, Toll-like receptor-4. PubmedID 15379975 Title Signal

  5. Toll-Like Receptor 2- and 6-Mediated Stimulation by Macrophage-Activating Lipopeptide 2 Induces Lipopolysaccharide (LPS) Cross Tolerance in Mice, Which Results in Protection from Tumor Necrosis Factor Alpha but in Only Partial Protection from Lethal LPS Doses

    Deiters, Ursula; Gumenscheimer, Marina; Galanos, Chris; Mühlradt, Peter F.

    2003-01-01

    Patients or experimental animals previously exposed to lipopolysaccharide (LPS) become tolerant to further LPS challenge. We investigated the potential of the macrophage-activating lipopeptide 2 (MALP-2) to induce in vivo cross tolerance to tumor necrosis factor alpha (TNF-α) and LPS. MALP-2-induced tolerance could be of practical interest, as MALP-2 proved much less pyrogenic in rabbits than LPS. Whereas LPS signals via Toll-like receptor 4 (TLR4), MALP-2 uses TLR2 and TLR6. LPS-mediated cyt...

  6. Anti-Inflammatory Activity of Fruit Fractions in Vitro, Mediated through Toll-Like Receptor 4 and 2 in the Context of Inflammatory Bowel Disease

    Noha Ahmed Nasef

    2014-11-01

    Full Text Available Pattern recognition receptors such as Toll-Like Receptor 2 (TLR2 and 4 (TLR4 are important in detecting and responding to stress and bacterial stimuli. Defect or damage in the TLR2 and TLR4 pathways can lead to sustained inflammation, characteristic of inflammatory bowel disease (IBD. The goal of this study was to identify fruit fractions that can be tested further to develop them as complementary therapies for IBD. In order to do this, we identified fruit fractions that mediate their anti-inflammatory response through the TLR4 and TLR2 pathway. Human Embryonic Kidney (HEK-hTLR4 and hTLR2 cells were stimulated with their respective ligands to induce inflammation. These cells were treated with one of the 12 fractionated fruits and the inflammatory effect measured. 10 of the fruits came up as anti-inflammatory in the hTLR4 assay and nine in the hTLR2 assays. Many of the fruit fractions mediated their anti-inflammatory actions either mainly in their hydrophobic fractions (such as elderberry or hydrophilic fractions (such as red raspberry, or both. The strongest anti-inflammatory effects were seen for feijoa and blackberry. This study shows that fruits can have multiple fractions eliciting anti-inflammatory effects in a pathway specific manner. This suggests that the compounds found in fruits can act together to produce health benefits by way of reducing inflammation. Exploiting this property of fruits can help develop complimentary therapies for inflammatory diseases.

  7. Toll-like receptors and cancer: MYD88 mutation and inflammation

    James Q Wang

    2014-07-01

    Full Text Available Pattern recognition receptors (PRRs expressed on immune cells are crucial for the early detection of invading pathogens, in initiating early innate immune response and in orchestrating the adaptive immune response. PRRs are activated by specific pathogen-associated molecular patterns (PAMPs that are present in pathogenic microbes or nucleic acids of viruses or bacteria. However, inappropriate activation of these PRRs, such as the Toll-like receptors (TLRs, due to genetic lesions or chronic inflammation has been demonstrated to be a major cause of many haematological malignancies. Gain-of-function mutations in the TLR adaptor protein MYD88 found in 39% of the activated B cell type of diffuse large B cell lymphomas (ABC-DLBCL and almost 100% of Waldenström’s macroglobulinemia (WM further highlight the involvement of TLRs in these malignancies. MYD88 mutations result in the chronic activation of TLR signalling pathways, thus the constitutive activation of the transcription factor NFκB to promote cell survival and proliferation. These recent insights into TLR pathway driven malignancies warrant the need for a better understanding of TLRs in cancers and the development of novel anti-cancer therapies targeting TLRs. This review focuses on Toll-like receptors function and signalling in normal or inflammatory conditions, and how mutations can also hijack the TLR signalling pathways to give rise to cancer. Lastly, we discuss how potential therapeutic agents could be used to restore normal responses to TLRs and have long lasting anti-tumour effects.

  8. Important role for Toll-like receptor 9 in host defense against meningococcal sepsis

    Sjölinder, Hong; Mogensen, Trine; Kilian, Mogens;

    2008-01-01

    Neisseria meningitidis is a leading cause of meningitis and sepsis. The pathogenesis of meningococcal disease is determined by both bacterial virulence factors and the host inflammatory response. Toll-like receptors (TLRs) are prominent activators of the inflammatory response, and TLR2, -4, and -9...... have been reported to be involved in the host response to N. meningitidis. While TLR4 has been suggested to play an important role in early containment of infection, the roles of TLR2 and TLR9 in meningococcal disease are not well described. Using a model for meningococcal sepsis, we report that TLR9...

  9. P2X4 receptor in the dorsal horn partially contributes to brain-derived neurotrophic factor oversecretion and toll-like receptor-4 receptor activation associated with bone cancer pain.

    Jin, Xiao-Hong; Wang, Li-Na; Zuo, Jian-Ling; Yang, Jian-Ping; Liu, Si-Lan

    2014-12-01

    Previous studies have suggested that the microglial P2X7 purinoceptor is involved in the release of tumor necrosis factor-α (TNFα) following activation of toll-like receptor-4 (TLR4), which is associated with nociceptive behavior. In addition, this progress is evoked by the activation of the P2X4 purinoceptor (P2X4R). Although P2X4R is also localized within spinal microglia in the dorsal horn, little is known about its role in cancer-induced bone pain (CIBP), which is in some ways unique. With the present rat model of CIBP, we demonstrate a critical role of the microglial P2X4R in the enhanced nociceptive transmission, which is associated with TLR4 activation and secretion of brain-derived neurotrophic factor (BDNF) and TNFα in the dorsal horn. We assessed mechanical threshold and spontaneous pain of CIBP rats. Moreover, P2X4R small interfering RNA (siRNA) was administered intrathecally, and real-time PCR, Western blots, immunofluorescence histochemistry, and ELISA were used to detect the expression of P2X4R, TLR4, OX-42, phosphorylated-p38 MAPK (p-p38), BDNF, and TNFα. Compared with controls, intrathecal injection of P2X4R siRNA could prevent nociceptive behavior induced by ATP plus lipopolysaccharide and CIBP and reduce the expression of P2X4R, TLR4, p-p38, BDNF, and TNFα. In addition, the increase of BDNF protein in rat microglial cells depended on P2X4 receptor signaling, which is partially associated with TLR4 activation. The ability of microglial P2X4R to activate TLR4 in spinal cord leading to behavioral hypersensitivity and oversecretion of BDNF could provide an opportunity for the prevention and treatment of CIBP. PMID:24984884

  10. The role of Toll-like receptors in the pathogenesis of allergic diseases – where is the truth?

    Anna Dębińska; Andrzej Boznański

    2014-01-01

    Toll-like receptors (TLRs) are pattern recognition receptors crucial for the innate and adaptive immune response to pathogen-associated molecular patterns (PAMPs). TLR stimulation via microbial products activates antigen-presenting cells, influences the function of T regulatory cells (Treg), determines the Th1/Th2 balance and Th17 cell differentiation, and controls cytokine production in mast cells and activation of eosinophils. The role of TLR receptors in pathogenesis of allergic diseases r...

  11. [Significance of Toll-like receptors in the pathophysiology of surgical sepsis].

    Romics, Laszlo Jr

    2012-02-03

    The discovery of Toll-like receptors has substantially changed our knowledge of pathogen recognition. 11 Toll-like receptors have so far been described in humans. These recognize distinct pathogen associated molecular patterns, as well as endogenous ligands and small molecular synthetic compounds. TLRs have a multifunctional role in pathogen-triggered immune responses and represent an important connection between the "innate" and "adaptive" immunity. The role of the TLRs in the recognition of pathogens renders them a key figure in the activation of the immune response during surgical sepsis. However, emerging evidence points to a fundamental role in tumorigenesis, transplantation, wound healing, atherogenesis and inflammatory bowel disease. The aim hence was to review experimental data pertaining to the activation of TLR signalling pathways in conditions associated with surgical sepsis. A systematic review of the literature was undertaken by searching the MEDLINE database for the period 1966-2004 without language restriction. The paper also analyses the possible therapeutic utilization of the TLR signalling pathways in surgical sepsis.

  12. Cleavage of fibrinogen by proteinases elicits allergic responses through Toll-like receptor 4.

    Millien, Valentine Ongeri; Lu, Wen; Shaw, Joanne; Yuan, Xiaoyi; Mak, Garbo; Roberts, Luz; Song, Li-Zhen; Knight, J Morgan; Creighton, Chad J; Luong, Amber; Kheradmand, Farrah; Corry, David B

    2013-08-16

    Proteinases and the innate immune receptor Toll-like receptor 4 (TLR4) are essential for expression of allergic inflammation and diseases such as asthma. A mechanism that links these inflammatory mediators is essential for explaining the fundamental basis of allergic disease but has been elusive. Here, we demonstrate that TLR4 is activated by airway proteinase activity to initiate both allergic airway disease and antifungal immunity. These outcomes were induced by proteinase cleavage of the clotting protein fibrinogen, yielding fibrinogen cleavage products that acted as TLR4 ligands on airway epithelial cells and macrophages. Thus, allergic airway inflammation represents an antifungal defensive strategy that is driven by fibrinogen cleavage and TLR4 activation. These findings clarify the molecular basis of allergic disease and suggest new therapeutic strategies. PMID:23950537

  13. Non-stereoselective reversal of neuropathic pain by naloxone and naltrexone: involvement of toll-like receptor 4 (TLR4)

    Hutchinson, Mark R; Zhang, Yingning; Brown, Kimberley; Coats, Benjamen D.; Shridhar, Mitesh; Sholar, Paige W.; Patel, Sonica J.; Crysdale, Nicole Y.; Harrison, Jacqueline A.; Maier, Steven F.; Rice, Kenner C.; Watkins, Linda R.

    2008-01-01

    Although activated spinal cord glia contribute importantly to neuropathic pain, how nerve injury activates glia remains controversial. It has recently been proposed, on the basis of genetic approaches, that toll-like receptor 4 (TLR4) may be a key receptor for initiating microglial activation following L5 spinal nerve injury. The present studies extend this idea pharmacologically by showing that TLR4 is key for maintaining neuropathic pain following sciatic nerve chronic constriction injury (...

  14. DMPD: Signaling to NF-kappaB by Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 18029230 Signaling to NF-kappaB by Toll-like receptors. Kawai T, Akira S. Trends Mo...l Med. 2007 Nov;13(11):460-9. Epub 2007 Oct 29. (.png) (.svg) (.html) (.csml) Show Signaling to NF-kappaB by... Toll-like receptors. PubmedID 18029230 Title Signaling to NF-kappaB by Toll-like receptors. Authors Kawai T

  15. Structure–activity correlations of variant forms of the B pentamer of Escherichia coli type II heat-labile enterotoxin LT-IIb with Toll-like receptor 2 binding

    Structural data for the S74D variant of the pentameric B subunit of type II heat-labile enterotoxin of Escherichia coli reveal a smaller pore opening that may explain its reduced Toll-like receptor binding affinity compared to that of the wild type enterotoxin. The explanation for the enhanced Toll-like receptor binding affinity of the S74A variant is more complex than simply being attributed to the pore opening. The pentameric B subunit of the type II heat-labile enterotoxin of Escherichia coli (LT-IIb-B5) is a potent signaling molecule capable of modulating innate immune responses. It has previously been shown that LT-IIb-B5, but not the LT-IIb-B5 Ser74Asp variant [LT-IIb-B5(S74D)], activates Toll-like receptor (TLR2) signaling in macrophages. Consistent with this, the LT-IIb-B5(S74D) variant failed to bind TLR2, in contrast to LT-IIb-B5 and the LT-IIb-B5 Thr13Ile [LT-IIb-B5(T13I)] and LT-IIb-B5 Ser74Ala [LT-IIb-B5(S74A)] variants, which displayed the highest binding activity to TLR2. Crystal structures of the Ser74Asp, Ser74Ala and Thr13Ile variants of LT-IIb-B5 have been determined to 1.90, 1.40 and 1.90 Å resolution, respectively. The structural data for the Ser74Asp variant reveal that the carboxylate side chain points into the pore, thereby reducing the pore size compared with that of the wild-type or the Ser74Ala variant B pentamer. On the basis of these crystallographic data, the reduced TLR2-binding affinity of the LT-IIb-B5(S74D) variant may be the result of the pore of the pentamer being closed. On the other hand, the explanation for the enhanced TLR2-binding activity of the LT-IIb-B5(S74A) variant is more complex as its activity is greater than that of the wild-type B pentamer, which also has an open pore as the Ser74 side chain points away from the pore opening. Data for the LT-IIb-B5(T13I) variant show that four of the five variant side chains point to the outside surface of the pentamer and one residue points inside. These data are consistent with

  16. Toll-Like Receptor 2 as a Regulator of Oral Tolerance in the Gastrointestinal Tract

    Matthew C. Tunis

    2014-01-01

    Full Text Available Food allergy, other adverse immune responses to foods, inflammatory bowel disease, and eosinophilic esophagitis have become increasingly common in the last 30 years. It has been proposed in the “hygiene hypothesis” that dysregulated immune responses to environmental microbial stimuli may modify the balance between tolerance and sensitization in some patients. Of the pattern recognition receptors that respond to microbial signals, toll-like receptors (TLRs represent the most investigated group. The relationship between allergy and TLR activation is currently at the frontier of immunology research. Although TLR2 is abundant in the mucosal environment, little is known about the complex relationship between bystander TLR2 activation by the commensal microflora and the processing of oral antigens. This review focuses on recent advances in our understanding of the relationship between TLR2 and oral tolerance, with an emphasis on regulatory T cells, eosinophils, B cells, IgA, intestinal regulation, and commensal microbes.

  17. Toll-like receptor-2 mediates mycobacteria-induced proinflammatory signaling in macrophages

    Underhill, David M; Ozinsky, Adrian; Smith, Kelly D.; Aderem, Alan

    1999-01-01

    The recognition of mycobacterial cell wall components causes macrophages to secrete tumor necrosis factor α (TNF-α) and other cytokines that are essential for the development of a protective inflammatory response. We show that toll-like receptors are required for the induction of TNF-α in macrophages by Mycobacterium tuberculosis. Expression of a dominant negative form of MyD88 (a signaling component required for toll-like receptor signaling) in a mouse macrophage cell line blocks TNF-α produ...

  18. A new Vitreoscilla filiformis extract grown on spa water-enriched medium activates endogenous cutaneous antioxidant and antimicrobial defenses through a potential Toll-like receptor 2/protein kinase C, zeta transduction pathway.

    Mahe, Yann F; Perez, Marie-Jesus; Tacheau, Charlotte; Fanchon, Chantal; Martin, Richard; Rousset, Françoise; Seite, Sophie

    2013-01-01

    Vitreoscilla filiformis (VF) biomass (VFB) has been widely used in cosmetic preparations and shown to modulate the major inducible free-radical scavenger mitochondrial superoxide dismutase in skin cells. By adding La Roche-Posay (LRP) thermal spring water to the VF culture medium, we obtained a biomass (LRP-VFB) with a similar mitochondrial superoxide dismutase activation capacity to VF. Also, the new biomass more powerfully stimulated mRNA expression and antimicrobial peptides in reconstructed epidermis. Interestingly, a predictive computer model that analyzed transducing events within skin epidermal cells suggested that this protective activity may involve the Toll-like receptor 2/protein kinase C, zeta transduction pathway. Protein kinase C, zeta inhibition was effectively shown to abolish VFB-induced gene stimulation and confirmed this hypothesis. This thus opens new avenues for investigation into the improvement of skin homeostatic defense in relation to the control of its physiological microbiota and innate immunity. PMID:24039440

  19. Dynamic evolution of toll-like receptor multigene families in echinoderms

    Katherine M Buckley

    2012-06-01

    Full Text Available The genome of the purple sea urchin, Strongylocentrotus purpuratus, was the first to be sequenced from a long-lived large invertebrate. Analysis of this genome uncovered a surprisingly complex immune system in which the moderately sized sets of pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR genes, more than 200 Nod-like receptors and 1095 scavenger receptor cysteine-rich domains, a ten-fold expansion relative to vertebrates. Given their stereotypic structure and simple intron-exon architecture, the TLRs are the most tractable of these families for more detailed analysis. An immune defense role for these receptors is suggested by their sequence diversity and expression in immunologically active tissues, including phagocytes. This complexity of the sea urchin TLR multigene families largely derives from expansions that are independent of those in vertebrates and protostomes, although a small family of TLRs with structure similar to that of Drosophila Toll likely originated in an ancient eumetazoan ancestor. Several other invertebrate deuterostome genomes have been sequenced, including the cephalochordate, Branchiostoma floridae and the sea urchin Lytechinus variegatus, as well as partial sequences from two other sea urchin species. Here, we present an analysis of the invertebrate deuterostome TLRs with emphasis on the echinoderms. Representatives of most of the S. purpuratus TLR subfamilies and homologs of the protostome-like sequences are found in L. variegatus. The phylogeny of these genes within sea urchins highlights lineage-specific expansions at higher resolution than is evident at the phylum level. These analyses identify quickly evolving TLR subfamilies that are likely to have novel functions and other, more stable, subfamilies that may function similarly to those of vertebrates.

  20. Toll-like receptor 2 activation by β2→1-fructans protects barrier function of t84 human intestinal epithelial cells in a chain length-dependent manner

    Vogt, L.M.; Meyer, D.; Pullens, G.; Faas, M.M.; Venema, K.; Ramasamy, U.; Schols, H.A.; Vos, P. de

    2014-01-01

    Dietary fiber intake is associated with lower incidence and mortality from disease, but the underlying mechanisms of these protective effects are unclear.We hypothesized that β2→1-fructan dietary fibers confer protection on intestinal epithelial cell barrier function via Toll-like receptor 2 (TLR2),

  1. DMPD: Toll-like receptors, Notch ligands, and cytokines drive the chronicity of lunginflammation. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 18073395 Toll-like receptors, Notch ligands, and cytokines drive the chronicity of lung...ors, Notch ligands, and cytokines drive the chronicity of lunginflammation. Authors Raymond T, Schaller M, H...2007 Dec;4(8):635-41. (.png) (.svg) (.html) (.csml) Show Toll-like receptors, Notch ligands, and cytokines d...rive the chronicity of lunginflammation. PubmedID 18073395 Title Toll-like recept

  2. The Role of Fatty Acids on Toll-like Receptor 4 Regulation of Substrate Metabolism with Obesity

    McMillan, Ryan P

    2009-01-01

    Growing evidence suggests that obesity and associated metabolic dysregulation occurs in concert with chronic low-grade inflammation. Toll-like receptors (TLR) are transmembrane receptors that play an important role in innate immunity and the induction of inflammatory responses. Our laboratory has observed that TLR4 expression is elevated in the skeletal muscle of obese humans and is associated with reduced fatty acid (FA) oxidation and increased lipid synthesis. Additionally, activation of th...

  3. Innate immune receptor Toll-like receptor 4 signalling in neuropsychiatric diseases.

    García Bueno, B; Caso, J R; Madrigal, J L M; Leza, J C

    2016-05-01

    The innate immunity is a stereotyped first line of defense against pathogens and unspecified damage signals. One of main actors of innate immunity are the Toll-like receptors (TLRs), and one of the better characterized members of this family is TLR-4, that it is mainly activated by Gram-negative bacteria lipopolysaccharide. In brain, TLR-4 organizes innate immune responses against infections or cellular damage, but also possesses other physiological functions. In the last years, some evidences suggest a role of TLR-4 in stress and stress-related neuropsychiatric diseases. Peripheral and brain TLR-4 activation triggers sickness behavior, and its expression is a risk factor of depression. Some elements of the TLR-4 signaling pathway are up-regulated in peripheral samples and brain post-mortem tissue from depressed and suicidal patients. The "leaky gut" hypothesis of neuropsychiatric diseases is based on the existence of an increase of the intestinal permeability which results in bacterial translocation able to activate TLR-4. Enhanced peripheral TLR-4 expression/activity has been described in subjects diagnosed with schizophrenia, bipolar disorder and in autistic children. A role for TLR-4 in drugs abuse has been also proposed. The therapeutic potential of pharmacological/genetic modulation of TLRs signaling pathways in neuropsychiatry is promising, but a great preclinical/clinical scientific effort is still needed. PMID:26905767

  4. Toll-like receptors and NOD-like receptors in rheumatic diseases.

    McCormack, William J

    2012-02-01

    The past 10 years have seen the description of families of receptors that drive proinflammatory cytokine production in infection and tissue injury. Two major classes have been examined in the context of inflammatory joint disease--the Toll-like receptors (TLRs) and NOD-like receptors (NLRs). TLRs such as TLR2 and TLR4 are being implicated in the pathology of rheumatoid arthritis, ankylosing spondylitis, lyme arthritis and osteoarthritis. Nalp3 has been identified as a key NLR for IL-1beta production and has been shown to have a particular role in gout. These findings present new therapeutic opportunities, possibly allowing for the replacement of biologics with small molecule inhibitors.

  5. DMPD: Toll-like receptors and RNA helicases: two parallel ways to trigger antiviralresponses. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 16762830 Toll-like receptors and RNA helicases: two parallel ways to trigger antiviralresponse...-like receptors and RNA helicases: two parallel ways to trigger antiviralresponses. PubmedID 16762830 Title ...Toll-like receptors and RNA helicases: two parallel ways to trigger antiviralresponse

  6. Toll-like receptor cascade and gene polymorphism in host–pathogen interaction in Lyme disease

    Rahman S

    2016-05-01

    Full Text Available Shusmita Rahman,1 Maria Shering,2 Nicholas H Ogden,3 Robbin Lindsay,4 Alaa Badawi1 1National Microbiology Laboratory, Public Health Agency of Canada, Toronto, 2Faculty of Arts and Science, University of Toronto, Toronto, ON, 3National Microbiology Laboratory, Public Health Agency of Canada, Saint-Hyacinthe, QC, 4National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada Abstract: Lyme disease (LD risk occurs in North America and Europe where the tick vectors of the causal agent Borrelia burgdorferi sensu lato are found. It is associated with local and systemic manifestations, and has persistent posttreatment health complications in some individuals. The innate immune system likely plays a critical role in both host defense against B. burgdorferi and disease severity. Recognition of B. burgdorferi, activation of the innate immune system, production of proinflammatory cytokines, and modulation of the host adaptive responses are all initiated by Toll-like receptors (TLRs. A number of Borrelia outer-surface proteins (eg, OspA and OspB are recognized by TLRs. Specifically, TLR1 and TLR2 were identified as the receptors most relevant to LD. Several functional single-nucleotide polymorphisms have been identified in TLR genes, and are associated with varying cytokines types and synthesis levels, altered pathogen recognition, and disruption of the downstream signaling cascade. These single-nucleotide polymorphism-related functional alterations are postulated to be linked to disease development and posttreatment persistent illness. Elucidating the role of TLRs in LD may facilitate a better understanding of disease pathogenesis and can provide an insight into novel therapeutic targets during active disease or postinfection and posttreatment stages. Keywords: Lyme disease, Toll-like receptors, Borrelia lipoproteins, genetic polymorphisms, host–pathogen interaction 

  7. Toll-like receptors: cellular signal transducers for exogenous molecular patterns causing immune responses.

    Kirschning, C J; Bauer, S

    2001-09-01

    Innate immunity initiates protection of the host organism against invasion and subsequent multiplication of microbes by specific recognition. Germ line-encoded receptors have been identified for microbial products such as mannan, lipopeptide, peptidoglycan (PGN), lipoteichoic acid (LTA), lipopolysaccharide (LPS), and CpG-DNA. The Drosophila Toll protein has been shown to be involved in innate immune response of the adult fruitfly. Members of the family of Toll-like receptors (TLRs) in vertebrates have been implicated as pattern recognition receptors (PRRs). Ten TLRs are known and six of these have been demonstrated to mediate cellular activation by distinct microbial products. TLR4 has been implicated as activator of adaptive immunity, and analysis of systemic LPS responses in mice led to the identification of LPS-resistant strains instrumental in its identification as a transmembrane LPS signal transducer. Structural similarities between TLRs and receptor molecules involved in immune responses such as CD14 and the IL-1 receptors (IL-1Rs), as well as functional analysis qualified TLR2 as candidate receptor for LPS and other microbial products. Targeted disruption of the TLR9 gene in mice led to identification of TLR9 as CpG-DNA signal transducer. Involvement of TLR5 in cell activation by bacterial flagellin has been demonstrated. Further understanding of recognition and cellular signaling activated through the ancient host defense system represented by Toll will eventually lead to means for its therapeutic modulation. PMID:11680785

  8. Laquinimod prevents cuprizone-induced demyelination independent of Toll-like receptor signaling

    Menken, Lena; Hayardeny, Liat; Hanisch, Uwe-Karsten; Brück, Wolfgang

    2016-01-01

    Objective: To test whether Toll-like receptor (TLR) signaling plays a key role for reduced nuclear factor B (NF-κB) activation after laquinimod treatment in the model of cuprizone-induced demyelination, oligodendrocyte apoptosis, inflammation, and axonal damage. Methods: Ten-week-old C57BL/6J, TLR4−/−, and MyD88−/− mice received 0.25% cuprizone for 6 weeks and were treated daily with 25 mg/kg laquinimod or vehicle. After 6 weeks of demyelination, extent of demyelination, oligodendrocyte density, microglia infiltration, and axonal damage were analyzed in the corpus callosum. Additionally, we analyzed primary mouse astrocytes from C57BL/6J, TLR4−/−, MyD88−/−, and TRIF−/− mice for alteration in NF-κB signaling. Results: Vehicle-treated controls from C57BL/6J, TLR4−/−, and MyD88−/− mice displayed extensive callosal demyelination as well as microglial activation. In contrast, mice treated with 25 mg/kg laquinimod showed mainly intact callosal myelin. The demyelination score was significantly higher in all untreated mice compared to mice treated with laquinimod. There were significantly fewer APP-positive axonal spheroids, Mac3-positive macrophages/microglia, and less oligodendrocyte apoptosis in the corpus callosum of laquinimod-treated mice in comparison to untreated controls. Stimulated primary mouse astrocytes from laquinimod-treated groups show reduced NF-κB activation compared to vehicle-treated controls. Conclusions: Our results confirm that laquinimod prevents demyelination in the cuprizone mouse model for multiple sclerosis via downregulation of NF-κB activation. This laquinimod effect, however, does not involve upstream Toll-like receptor signaling. PMID:27231712

  9. Relationship between Toll-Like Receptor 8 Gene Polymorphisms and Pediatric Pulmonary Tuberculosis

    Nazan Dalgic

    2011-01-01

    Full Text Available Objectives: Genetic variants in Toll-like receptors (TLRs are considered a potential indicator for host susceptibility to and outcome of several infectious diseases including tuberculosis. The aim of this study was to determine whether −129 C/G and Met1Val polymorphisms of TLR8 were associated with pediatric pulmonary tuberculosis in Turkish population.

  10. First evidence of independent pseudogenization of Toll-like receptor 5 in passerine birds

    Bainová, H.; Králová, Tereza; Bryjová, Anna; Albrecht, Tomáš; Bryja, Josef; Vinkler, M.

    2014-01-01

    Roč. 45, č. 1 (2014), s. 151-155. ISSN 0145-305X R&D Projects: GA ČR GAP505/10/1871 Institutional support: RVO:68081766 Keywords : Birds * Expression * Innate immunity * Toll-like receptor 5 * Pseudogene * Flagellin Subject RIV: EG - Zoology Impact factor: 2.815, year: 2014

  11. Inter- and intraspecific polymorphism in passerine Toll-like receptor 4

    Bainová, H.; Bryjová, Anna; Promerová, Marta; Bryja, Josef; Johnsen, A.; Lifjeld, J. T.; Albrecht, Tomáš; Vinkler, Michal

    Tübingen: Eberhard Karls Universität Tübingen, 2011. s. 492. [Congress of the European Society for Evolution ary Biology ESEB /13./. 20.08.2011-25.08.2011, Tübingen] Institutional research plan: CEZ:AV0Z60930519 Keywords : passerine * Toll-like receptor Subject RIV: EG - Zoology

  12. Differences in evolution of Toll-like receptors 4 and 7 genes in wild rodents (Murinae)

    Fornůsková, Alena; Vinkler, Michal; Galan, M.; Morand, S.; Charbonnel, N.; Bryja, Josef; Cosson, J.-F.

    Vantaa: Finnish Forest Research Institute, 2012 - (Henttonen, H.; Huitu, O.). s. 77 ISBN 978-951-40-2374-3. [Rodens et Spatium /13./. 16.07.2012-20.07.2012, Rovaniemi] Institutional support: RVO:68081766 Keywords : Toll-like receptors Subject RIV: EG - Zoology

  13. Evolution of toll-like receptors 4 and 7 genes in wild rodents (Murinae)

    Fornůsková, Alena; Galan, M.; Cerqueira, F.; Bryja, Josef; Charbonnel, N.; Cosson, J.-F.

    Paris: Université P. et M. Curie, 2011. s. 12 [European Congress of Mammalogy /7./. 19.07.2011-23.07.2011, Paris] Institutional research plan: CEZ:AV0Z60930519 Keywords : rodents * toll-like receptors Subject RIV: EG - Zoology http://www.alphavisa.com/ecm2011/pdf/ECM2011-Abstract_Book.pdf

  14. Intra-uterine Growth Restriction Downregulates the Hepatic Toll Like Receptor-4 Expression and Function

    Ozlem Equils; Sapna Singh; Semra Karaburun; Daning Lu; Manikkavasagar Thamotharan; Devaskar, Sherin U.

    2005-01-01

    Maternal starvation is a significant cause of intrauterine growth restriction (IUGR) in the world and increases the risk of infection in the neonate. We examined the effect of maternal starvation on Toll like receptor (TLR)4 expression in hepatic, splenic and intestinal tissues obtained from the adult IUGR offspring of prenatal calorie restricted rats. The hepatic TLR4 protein concentration was undetectable in the...

  15. MECHANISMS OF ANTIINFECTIOUS FUNCTIONS OF INNATE IMMUNITY: ROLE OF TOLL-LIKE RECEPTORS

    S. I. Suskov

    2012-05-01

    Full Text Available This review describes the main role of toll-like receptors of innate immunity for pathogen recognition; signaling; production of inflammatory response. Also Interrelation of innate and adaptive Immunity in conditions of pathology and organ transplantation were considered. 

  16. Structure and variability of Toll-like receptor genes in Grey Partridge (Perdix perdix)

    Tomášek, Oldřich; Vinkler, Michal; Bainová, H.; Opatová, Pavlína; Bryjová, Anna; Bryja, Josef; Albrecht, Tomáš

    Tübingen : Eberhard Karls Universität Tübingen, 2011. s. 1030. [ Congress of the European Society for Evolutionary Biology ESEB /13./. 20.08.2011-25.08.2011, Tübingen] Institutional research plan: CEZ:AV0Z60930519 Keywords : Grey Partridge * Toll-like receptor Subject RIV: EG - Zoology

  17. Toll-like Receptors Involved in the Pathogenesis of Experimental Candida albicans Keratitis

    Yuan, Xiaoyong; Wilhelmus, Kirk R.

    2010-01-01

    Toll-like receptors mediate innate immune responses at the onset of infection, including keratomycosis. Based on corneal gene expression studies and the use of TLR-deficient mice, TLR2 appears partly responsible for the release of proinflammatory cytokines and chemokines that recruit leukocytes to restrain fungal growth during Candida albicans keratitis.

  18. Toll-like receptor 2 ligands regulate monocyte Fcγ receptor expression and function.

    Shah, Prexy; Fatehchand, Kavin; Patel, Hemal; Fang, Huiqing; Justiniano, Steven E; Mo, Xiaokui; Jarjoura, David; Tridandapani, Susheela; Butchar, Jonathan P

    2013-04-26

    Fcγ receptor (FcγR) clustering on monocytes/macrophages results in phagocytosis and inflammatory cytokine production, which serve to eliminate antibody-opsonized targets and activate neighboring immune cells. Toll-like receptor 2 (TLR2), which recognizes a range of both bacterial and fungal components, elicits strong proinflammatory responses in these cells when stimulated by ligands, either natural or synthetic. Thus, we explored the possibility that TLR2 agonists could strengthen FcγR activity within the context of antibody therapy. Human peripheral blood monocytes treated with the TLR2 agonist Pam2CSK4 showed significantly enhanced FcγR-mediated cytokine production as well as phagocytic ability. An examination of the molecular mechanism behind this enhancement revealed increased expression of both FcγRIIa and the common γ subunit following Pam2CSK4 treatment. Interestingly however, expression of the inhibitory receptor FcγRIIb was also modestly increased. Further investigation revealed that Pam2CSK4 also dramatically decreased the expression of SHIP, the major mediator of FcγRIIb inhibitory activity. Using a murine Her2/neu solid tumor model of antibody therapy, we found that Pam2CSK4 significantly enhanced the ability of anti-Her2 antibody to reduce the rate of tumor growth. To verify that the FcγR enhancement was not unique to the diacylated Pam2CSK4, we also tested Pam3CSK4, a related triacylated TLR2 agonist. Results showed significant enhancement in FcγR function and expression. Taken together, these findings indicate that TLR2 activation can positively modulate FcγR and suggest that TLR2 agonists should be considered for testing as adjuvants for antitumor antibody therapy. PMID:23504312

  19. Toll-like receptor signaling is functional in immune cells of the endangered Tasmanian devil.

    Patchett, Amanda L; Latham, Roger; Brettingham-Moore, Kate H; Tovar, Cesar; Lyons, A Bruce; Woods, Gregory M

    2015-11-01

    Devil facial tumour disease (DFTD) is a fatally transmissible cancer that threatens the Tasmanian devil population. As Tasmanian devils do not produce an immune response against DFTD cells, an effective vaccine will require a strong adjuvant. Activation of innate immune system cells through toll-like receptors (TLRs) could provide this stimulation. It is unknown whether marsupials, including Tasmanian devils, express functional TLRs. We isolated RNA from peripheral blood mononuclear cells and, with PCR, detected transcripts for TLRs 2, 3, 4, 5, 6, 7, 8, 9, 10 and 13. Stimulation of the mononuclear cells with agonists to these TLRs increased the expression of downstream TLR signaling products (IL1α, IL6, IL12A and IFNβ). Our data provide the first evidence that TLR signaling is functional in the mononuclear cells of the Tasmanian devil. Future DFTD vaccination trials will incorporate TLR agonists to enhance the immune response against DFTD. PMID:26182986

  20. Toll-like receptors, a double-edged sword in immunity to malaria

    Chen Jide; He Ying; Xu Wenyue; Huang Fusheng

    2009-01-01

    Toll-like receptors (TLRs) are a central component of innate immune system and play a major role as the initiator of the innate immune responses to defend against bacteria, viruses, parasite and other pathogens. During malaria infection, TLRs signaling pathways are initialed with the recognition of Plasmodium glycosylphosphatidylinositols (GPI) and hemozoin as pathogen-associated molecular patterns (PAMPs). And then, activation of TLRs signaling induces specific biological responses against malaria parasites invasion. However, TLRs are also involved in malaria pathogenesis and enhancement of immune tolerance and evasion for malaria infection. Moreover, malaria parasites regulate selectively TLRs expression on immune cells.Thus, these evidences indicated that TLRs have contrary roles on malaria infection. Understanding the complicated roles of TLRs on malaria infection will contribute us to design more effective anti-malaria drugs or vaccines.

  1. CPG-7909 (PF-3512676, ProMune): toll-like receptor-9 agonist in cancer therapy.

    Murad, Yanal M; Clay, Timothy M; Lyerly, H Kim; Morse, Michael A

    2007-08-01

    Stimulation of toll-like receptor (TLR)9 activates human plasmacytoid dendritic cells and B cells, and induces potent innate immune responses in preclinical tumor models and in patients. CpG oligodeoxynucleotides (ODNs) are TLR9 agonists that show promising results as vaccine adjuvants and in the treatment of cancers, infections, asthma and allergy. PF-3512676 (ProMune) was developed as a TLR9 agonist for the treatment of cancer as monotherapy and as an adjuvant in combination with chemo- and immunotherapy. Phase I and II trials have tested this drug in several hematopoietic and solid tumors. Pfizer has initiated Phase III trials to test PF-3512676 in combination with standard chemotherapy for non-small-cell lung cancer. PMID:17696823

  2. Expression of Toll-like receptors 2 and 4 in gingivitis and chronic periodontitis.

    Sarah S

    2006-01-01

    Full Text Available Periodontal disease is the major cause of adult tooth loss and is commonly characterized by a chronic inflammation caused by infection by oral bacteria. Members of Toll-like receptor (TLR family recognize conserved microbial structures, such as bacterial lipopolysaccharides, and activate signaling pathways that result in immune responses against microbial infections. The aim of the present study was to assess the mRNA expression of TLR-2 and TLR-4 in gingivitis and chronic periodontitis. Gingival tissue samples were collected from patients with chronic periodontitis, gingivitis, and healthy controls. Total RNA was extracted and RT-PCR was done for TLR-2 and TLR-4. The results showed that TLR-2 was significantly increased in gingivitis compared to TLR-4 expression and decreased in chronic periodontitis.

  3. Regulation of Toll-like receptors-dependent inflammatory response 

    Ewa Kowalczyk

    2013-03-01

    Full Text Available Toll-like receptors (TLRs are a pivotal part of our innate immune response. They recognize a wide variety of pathogens and instigate an immune response, thus facilitating the removal of the disease-causing agent. Due to the intense nature of this response its strict control is of keyimportance, as a prolonged inflammatory signal leads to carcinogenesis and autoimmune disorders. The signaling cascade initiated by the activated TLR is complex and consists of multiple stages. It involves a variety of adaptor proteins, protein kinases and effector transcription factors. The number of stages in this process enables many possible checkpoints and ways of regulation. Signal modulation involves differentiated expression of TLRs, splicing variants of their adaptorproteins, enzymes modifying proteins engaged in the cascade and many more. This review focuses on endogenous factors responsible for controlling the TLR-dependent inflammatory response as well as on pharmacological therapies designed for regulating the innate immune response.  

  4. Role of Toll-like receptors in lung innate defense against invasive aspergillosis. Distinct impact in immunocompetent and immunocompromized hosts.

    Chignard, Michel; Balloy, Viviane; Sallenave, Jean-Michel; Si-Tahar, Mustapha

    2007-09-01

    Toll-like receptors are key to pathogen recognition by a host and to the subsequent triggering of an innate immune response. Experimental and clinical evidence shows that defects in Toll-like receptors or in signaling pathways downstream from these receptors render hosts susceptible to various types of infection, including aspergillosis. Patients receiving an immunosuppressive regimen, including corticosteroid therapy or cytotoxic chemotherapy, are also susceptible to infections. Aspergillus fumigatus is an opportunistic pathogen that infects the lungs of immunosuppressed hosts. Here, we review the evidence that experimental inactivation of various Toll-like receptors and of their signaling pathways may worsen cases of invasive pulmonary aspergillosis. Moreover, the literature clearly indicates that the type of immunosuppression is very important, as it influences whether or not Toll-like receptors contribute to infection. The involvement of Toll-like receptors, based on the immunological status of the patient, should be considered if an immunosuppressive treatment must be administered. PMID:17604224

  5. DMPD: The negative regulation of Toll-like receptor and associated pathways. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17621314 The negative regulation of Toll-like receptor and associated pathways. Lan...g T, Mansell A. Immunol Cell Biol. 2007 Aug-Sep;85(6):425-34. Epub 2007 Jul 10. (.png) (.svg) (.html) (.csml) Show The... negative regulation of Toll-like receptor and associated pathways. PubmedID 17621314 Title The ne

  6. Reptile Toll-like receptor 5 unveils adaptive evolution of bacterial flagellin recognition

    Voogdt, Carlos G.P.; Bouwman, Lieneke I.; Kik, Marja J. L.; Wagenaar, Jaap A.; van Putten, Jos P. M.

    2016-01-01

    Toll-like receptors (TLR) are ancient innate immune receptors crucial for immune homeostasis and protection against infection. TLRs are present in mammals, birds, amphibians and fish but have not been functionally characterized in reptiles despite the central position of this animal class in vertebrate evolution. Here we report the cloning, characterization, and function of TLR5 of the reptile Anolis carolinensis (Green Anole lizard). The receptor (acTLR5) displays the typical TLR protein arc...

  7. Soluble toll like receptor 2 (TLR-2) is increased in saliva of children with dental caries

    Zhao, Alyssa; Blackburn, Corinne; Chin, Judith; Srinivasan, Mythily

    2014-01-01

    Background Dental caries is the most common microbial disease affecting mankind. Caries risk assessment methods, identification of biomarkers and vaccine development strategies are being emphasized to control the incidence of the largely preventable disease. Pattern recognition receptors such as the toll like receptors (TLR) have been implicated as modulators of host-microbial interactions. Soluble TLR-2 and its co-receptor, CD14 identified in saliva can bind the cell wall components of cario...

  8. Neu1 sialidase and matrix metalloproteinase-9 cross-talk regulates nucleic acid-induced endosomal TOLL-like receptor-7 and -9 activation, cellular signaling and pro-inflammatory responses.

    Abdulkhalek, Samar; Szewczuk, Myron R

    2013-11-01

    The precise mechanism(s) by which intracellular TOLL-like receptors (TLRs) become activated by their ligands remains unclear. Here, we report a molecular organizational G-protein coupled receptor (GPCR) signaling platform to potentiate a novel mammalian neuraminidase-1 (Neu1) and matrix metalloproteinase-9 (MMP-9) cross-talk in alliance with neuromedin B GPCR, all of which form a tripartite complex with TLR-7 and -9. siRNA silencing Neu1, MMP-9 and neuromedin-B GPCR in RAW-blue macrophage cells significantly reduced TLR7 imiquimod- and TLR9 ODN1826-induced NF-κB (NF-κB-pSer(536)) activity. Tamiflu, specific MMP-9 inhibitor, neuromedin B receptor specific antagonist BIM23127, and the selective inhibitor of whole heterotrimeric G-protein complex BIM-46174 significantly block nucleic acid-induced TLR-7 and -9 MyD88 recruitment, NF-κB activation and proinflammatory TNFα and MCP-1 cytokine responses. For the first time, Neu1 clearly plays a central role in mediating nucleic acid-induced intracellular TLR activation, and the interactions involving NMBR-MMP9-Neu1 cross-talk constitute a novel intracellular TLR signaling platform that is essential for NF-κB activation and pro-inflammatory responses. PMID:23827939

  9. Escherichia coli Strain Nissle 1917 Ameliorates Experimental Colitis via Toll-Like Receptor 2- and Toll-Like Receptor 4-Dependent Pathways

    Grabig, A.; Paclik, D.; Guzy, C.; Dankof, A.; Baumgart, D.C.; Erckenbrecht, J.; Raupach, B; Sonnenborn, U.; Eckert, J.; Schumann, R. R.; Wiedenmann, B; Dignass, A U; Sturm, A

    2006-01-01

    Toll-like receptors (TLRs) are key components of the innate immune system that trigger antimicrobial host defense responses. The aim of the present study was to analyze the effects of probiotic Escherichia coli Nissle strain 1917 in experimental colitis induced in TLR-2 and TLR-4 knockout mice. Colitis was induced in wild-type (wt), TLR-2 knockout, and TLR-4 knockout mice via administration of 5% dextran sodium sulfate (DSS). Mice were treated with either 0.9% NaCl or 107 E. coli Nissle 1917 ...

  10. Pleiotropic effects of Blastocystis spp. Subtypes 4 and 7 on ligand-specific toll-like receptor signaling and NF-κB activation in a human monocyte cell line.

    Joshua D W Teo

    Full Text Available Blastocystis spp. is a common enteric stramenopile parasite that colonizes the colon of hosts of a diverse array of species, including humans. It has been shown to compromise intestinal epithelial cell barrier integrity and mediate the production of pro-inflammatory cytokines and chemokines. Mucosal epithelial surfaces, including the intestinal epithelium, are increasingly recognized to perform a vital surveillance role in the context of innate immunity, through the expression of pathogen recognition receptors, such as Toll-like receptors (TLRs. In this study, we use the human TLR reporter monocytic cell line, THP1-Blue, which expresses all human TLRs, to investigate effects of Blastocystis on TLR activation, more specifically the activation of TLR-2, -4 and -5. We have observed that live Blastocystis spp. parasites and whole cell lysate (WCL alone do not activate TLRs in THP1-Blue. Live ST4-WR1 parasites inhibited LPS-mediated NF-κB activation in THP1-Blue. In contrast, ST7-B WCL and ST4-WR1 WCL induced pleiotropic modulation of ligand-specific TLR-2 and TLR-4 activation, with no significant effects on flagellin-mediated TLR-5 activation. Real time-qPCR analysis on SEAP reporter gene confirmed the augmenting effect of ST7-B on LPS-mediated NF-κB activation in THP1-Blue. Taken together, this is the first study to characterize interactions between Blastocystis spp. and host TLR activation using an in vitro reporter model.

  11. Decreased Toll-like receptor 8 expression and lower TNF-alpha synthesis in infants with acute RSV infection

    Gagro Alenka; Cepin-Bogovic Jasna; Aberle Neda; Vojvoda Valerija; Bendelja Kreso; Mlinaric-Galinovic Gordana; Rabatic Sabina

    2010-01-01

    Abstract Background Toll-like receptors (TLRs) are part of the innate immune system, able to recognize pathogen-associated molecular patterns and activate immune system upon pathogen challenge. Respiratory syncytial virus (RSV) is a RNA virus particularly detrimental in infancy. It could cause severe lower respiratory tract disease and recurrent infections related to inadequate development of anti-viral immunity. The reason could be inadequate multiple TLRs engagement, including TLR8 in recog...

  12. The Role of Toll Like Receptors in Pregnancy

    Reza Aflatoonian

    2013-01-01

    Full Text Available For many years, the innate immunity was of less interest than the adaptive immunitybecause it was perceived to have secondary importance in the functionality of theimmune system. During the past decades, with the advancement of knowledge aboutinnate immune system, interest in innate immunity has grown dramatically and thusits function has been extensively studied. Innate immunity plays fundamental rolesin the initiation and induction of adaptive immune responses. It consists of severalcells and receptors including natural killer (NK cells, macrophages (MQs, dendriticcells (DCs and pattern recognition receptors (PRRs. Two decades ago, Tolllike receptors (TLRs family was known as one of the important PRRs with uniquefunctions especially in protection against invading pathogens. Since the female reproductivetract has access to the outside environment and has a unique interactionwith different pathogens whether invading microorganisms or normal flora, allogenicsperm and semi allogenic fetus, it has an essential need for effective immuneresponses. It has therefore been suggested that TLRs may play important roles inthe immune regulation of the female reproductive tract. In addition, it has beendemonstrated that immune disturbance may be responsible for some adverse pregnancyoutcomes such as preeclampsia (PE, recurrent spontaneous abortion (RSAand intrauterine growth restriction (IUGR. Our focus in this review is to show theimportance of TLRs in pregnancy with emphasis on the expression of these receptorsin different tissues related to pregnancy.

  13. Toll-like receptor 4 decoy, TOY, attenuates gram-negative bacterial sepsis.

    Keehoon Jung

    Full Text Available Lipopolysaccharide (LPS, the Gram-negative bacterial outer membrane glycolipid, induces sepsis through its interaction with myeloid differentiation protein-2 (MD-2 and Toll-like receptor 4 (TLR4. To block interaction between LPS/MD-2 complex and TLR4, we designed and generated soluble fusion proteins capable of binding MD-2, dubbed TLR4 decoy receptor (TOY using 'the Hybrid leucine-rich repeats (LRR technique'. TOY contains the MD-2 binding ectodomain of TLR4, the LRR motif of hagfish variable lymphocyte receptor (VLR, and the Fc domain of IgG1 to make it soluble, productive, and functional. TOY exhibited strong binding to MD-2, but not to the extracellular matrix (ECM, resulting in a favorable pharmacokinetic profile in vivo. TOY significantly extended the lifespan, when administered in either preventive or therapeutic manners, in both the LPS- and cecal ligation/puncture-induced sepsis models in mice. TOY markedly attenuated LPS-triggered NF-kappaB activation, secretion of proinflammatory cytokines, and thrombus formation in multiple organs. Taken together, the targeting strategy for sequestration of LPS/MD-2 complex using the decoy receptor TOY is effective in treating LPS- and bacteria-induced sepsis; furthermore, the strategy used in TOY development can be applied to the generation of other novel decoy receptor proteins.

  14. Interaction between Cannabinoid System and Toll-Like Receptors Controls Inflammation.

    McCoy, Kathleen L

    2016-01-01

    Since the discovery of the endocannabinoid system consisting of cannabinoid receptors, endogenous ligands, and biosynthetic and metabolizing enzymes, interest has been renewed in investigating the promise of cannabinoids as therapeutic agents. Abundant evidence indicates that cannabinoids modulate immune responses. An inflammatory response is triggered when innate immune cells receive a danger signal provided by pathogen- or damage-associated molecular patterns engaging pattern-recognition receptors. Toll-like receptor family members are prominent pattern-recognition receptors expressed on innate immune cells. Cannabinoids suppress Toll-like receptor-mediated inflammatory responses. However, the relationship between the endocannabinoid system and innate immune system may not be one-sided. Innate immune cells express cannabinoid receptors and produce endogenous cannabinoids. Hence, innate immune cells may play a role in regulating endocannabinoid homeostasis, and, in turn, the endocannabinoid system modulates local inflammatory responses. Studies designed to probe the interaction between the innate immune system and the endocannabinoid system may identify new potential molecular targets in developing therapeutic strategies for chronic inflammatory diseases. This review discusses the endocannabinoid system and Toll-like receptor family and evaluates the interaction between them. PMID:27597805

  15. CD14+ cells are required for IL-12 response in bovine blood mononuclear cells activated with Toll-like receptor (TLR) 7 and TLR8 ligands.

    Buza, Joram; Benjamin, Ponn; Zhu, Jianzhung; Wilson, Heather L; Lipford, Grayson; Krieg, Arthur M; Babiuk, Lorne A; Mutwiri, George K

    2008-12-15

    Single-stranded viral RNA (ssRNA) was recently identified as the natural ligand for TLR7 and TLR8. ssRNA sequences from viruses, as well as their synthetic analogues stimulate innate immune responses in immune cells from humans and mice, but their immunostimulatory activity has not been investigated in ruminants. In the present investigations, we tested whether synthetic RNA oligoribonucleotides (ORN) can activate immune cells from cattle. In vitro incubation of bovine peripheral blood mononuclear cells (PBMCs) with ORN-induced production of IL-12, IFN-gamma and TNF-alpha. No significant induction of IFN-alpha was observed. Depletion of CD14+ cells from PBMC abrogated the IL-12 response and consequently the IFN-gamma response, suggesting that CD14+ cells are required for PBMC immune activation with ORN. Consistent with these findings, the putative receptors for ORN (TLR7 and TLR8) were expressed at higher levels in the CD14+ fraction than the CD14- PBMC fraction. Pre-treatment of PBMC with bafilomycin (an inhibitor of phagosomal acidification) prior to stimulation with ORN abolished the cytokine responses, confirming that the receptor(s) which mediate the ORN-induced responses are intracellular. These results demonstrate for the first time that the TLR7/8 agonist ORN's have strong immune stimulatory effects in cattle, and suggest that further investigation on the potential of TLR7/8 ligands to activate innate and adaptive immune responses in domestic animals are warranted. PMID:18789542

  16. Dynamic Evolution of Toll-Like Receptor Multigene Families in Echinoderms

    Buckley, Katherine M; Rast, Jonathan P.

    2012-01-01

    The genome sequence of the purple sea urchin, Strongylocentrotus purpuratus, a large and long-lived invertebrate, provides a new perspective on animal immunity. Analysis of this genome uncovered a highly complex immune system in which the gene families that encode homologs of the pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR) sequences, more than 200 Nod-like re...

  17. Toll-like receptor 4 gene polymorphism is associated with chronic periodontitis

    Ding, Yuan-Sheng; Zhao, Yue; Xiao,Yuan-Yuan; Zhao, Gang

    2015-01-01

    Toll-like receptors (TLRs) contribute to the immune response by recognizing patterns presented by bacteria and other pathogens. These receptors have been implicated in the inflammatory response that contributes to gingivitis and periodontitis. Conflicting reports have suggested that variations in the genes encoding TLRs, particularly TLR2 and TLR4, may influence susceptibility to periodontitis. In this study, the contribution of variations in the genes encoding TLR2 and TLR4 in the context of...

  18. Toll-like receptor 4 and interleukin 6 gene polymorphisms in Helicobacter pylori related diseases

    Pohjanen, V.-M. (Vesa-Matti)

    2016-01-01

    Abstract Helicobacter pylori is a Gram-negative bacterium, which infects the stomach of more than 50% of the population worldwide. In addition to being the most important risk factor for gastric cancer and peptic ulcers, H. pylori infection is a risk factor for several extra-digestive diseases including dyslipidemia. The consequences of having an H. pylori infection are significantly influenced by the inflammatory response of the host. The pattern recognition receptor Toll-like receptor 4...

  19. Trypanosoma cruzi and its components as exogenous mediators of inflammation recognized through Toll-like receptors.

    Gazzinelli, Ricardo T.; Campos, Marco A

    2004-01-01

    TRYPANOSOMA cruzi is the etiologic agent of Chagas' disease, a parasitic disease of enormous importance in Latin America. Herein we review the studies that revealed the receptors from innate immunity that are involved in the recognition of this protozoan parasite. We showed that the recognition of T. cruzi and its components occurs through Toll-like receptors (TLR) 2/CD14. Further, we showed in vivo the importance of the myeloid differentiation factor (MyD88), an adapter protein essential for...

  20. Differential expression of toll-like receptors in patients with irritable bowel syndrome.

    Brint, Elizabeth K

    2011-02-01

    The pathogenesis of irritable bowel syndrome (IBS) is poorly understood. One contributory factor may be low-grade mucosal inflammation, perhaps initiated by the microbiota. Toll-like receptors (TLRs) are a family of pathogen-recognition receptors of the innate immune system. The aim of this study was to evaluate the potential involvement of TLRs in IBS to further understand the involvement of the innate immune system in this complex disorder.

  1. Toll-Like Receptor-4 Dependent Small Intestinal Immune Responses Following Murine Arcobacter Butzleri Infection

    Heimesaat, Markus M.; Karadas, Gül; Fischer, André; Göbel, Ulf B.; Alter, Thomas; Bereswill, Stefan; Gölz, Greta

    2015-01-01

    Sporadic cases of gastroenteritis have been attributed to Arcobacter butzleri infection, but information about the underlying immunopathological mechanisms is scarce. We have recently shown that experimental A. butzleri infection induces intestinal, extraintestinal and systemic immune responses in gnotobiotic IL-10–/– mice. The aim of the present study was to investigate the immunopathological role of Toll-like Receptor-4, the receptor for lipopolysaccharide and lipooligosaccharide of Gram-ne...

  2. The 2′-O-methylation status of a single guanosine controls transfer RNA–mediated Toll-like receptor 7 activation or inhibition

    Jöckel, Stefanie; Nees, Gernot; Sommer, Romy; Zhao, Yang; Cherkasov, Dmitry; Hori, Hiroyuki; Ehm, Gundi; Schnare, Markus; Nain, Marianne; Kaufmann, Andreas; Bauer, Stefan

    2012-01-01

    Foreign RNA serves as pathogen-associated molecular pattern (PAMP) and is a potent immune stimulator for innate immune receptors. However, the role of single bacterial RNA species in immune activation has not been characterized in detail. We analyzed the immunostimulatory potential of transfer RNA (tRNA) from different bacteria. Interestingly, bacterial tRNA induced type I interferon (IFN) and inflammatory cytokines in mouse dendritic cells (DCs) and human peripheral blood mononuclear cells (...

  3. Toll-like receptors; their physiological role and signal transduction system.

    Takeuchi, O; Akira, S

    2001-04-01

    Drosophila Toll protein is a transmembrane receptor whose function is to recognize the invasion of microorganisms as well as to establish dorso-ventral polarity. Recently, mammalian homologues of Toll, designated as Toll-like receptors (TLRs) have been discovered. So far, six members (TLR1-6) have been reported and two of these, TLR2 and TLR4, have been shown to be essential for the recognition of distinct bacterial cell wall components. TLR2 discriminates peptidoglycan (PGN), lipoprotein, lipoarabinomannan (LAM) and zymosan, whereas TLR4 recognizes lipopolysaccharide (LPS), lipoteichoic acid (LTA) and Taxol. Bacterial components elicit the activation of an intracellular signaling cascade via TLR in a similar way to that occurs upon ligand binding to IL-1 receptor (IL-1R). This signaling pathway leads to the activation of a transcription factor NF-kappaB and c-Jun N-terminal kinase (JNK), which initiate the transcription of proinflammatory cytokine genes. Particularly, analysis of knockout mice revealed a pivotal role for MyD88 in the signaling of the TLR/IL-1R family. Taken together, TLRs and the downstream signaling pathway play a key role in innate immune recognition and in subsequent activation of adaptive immunity. PMID:11357875

  4. Prenatal activation of Toll-like receptors-3 by administration of the viral mimetic poly(I:C changes synaptic proteins, N-methyl-D-aspartate receptors and neurogenesis markers in offspring

    Forrest Caroline M

    2012-06-01

    Full Text Available Abstract Background There is mounting evidence for a neurodevelopmental basis for disorders such as autism and schizophrenia, in which prenatal or early postnatal events may influence brain development and predispose the young to develop these and related disorders. We have now investigated the effect of a prenatal immune challenge on brain development in the offspring. Pregnant rats were treated with the double-stranded RNA polyinosinic:polycytidylic acid (poly(I:C; 10 mg/kg which mimics immune activation occurring after activation of Toll-like receptors-3 (TLR3 by viral infection. Injections were made in late gestation (embryonic days E14, E16 and E18, after which parturition proceeded naturally and the young were allowed to develop up to the time of weaning at postnatal day 21 (P21. The brains of these animals were then removed to assess the expression of 13 different neurodevelopmental molecules by immunoblotting. Results Measurement of cytokine levels in the maternal blood 5 hours after an injection of poly(I:C showed significantly increased levels of monocyte chemoattractant protein-1 (MCP-1, confirming immune activation. In the P21 offspring, significant changes were detected in the expression of GluN1 subunits of NMDA receptors, with no difference in GluN2A or GluN2B subunits or the postsynaptic density protein PSD-95 and no change in the levels of the related small GTPases RhoA or RhoB, or the NMDA receptor modulator EphA4. Among presynaptic molecules, a significant increase in Vesicle Associated Membrane Protein-1 (VAMP-1; synaptobrevin was seen, with no change in synaptophysin or synaptotagmin. Proliferating Cell Nuclear Antigen (PCNA, as well as the neurogenesis marker doublecortin were unchanged, although Sox-2 levels were increased, suggesting possible changes in the rate of new cell differentiation. Conclusions The results reveal the induction by prenatal poly(I:C of selective molecular changes in the brains of P21 offspring

  5. Inter- and intraspecific polymorphism in passerine Toll-like receptor 4

    Bainová, H.; Bryjová, Anna; Promerová, Marta; Bryja, Josef; Lifjeld, J. T.; Johnsen, A.; Albrecht, Tomáš; Vinkler, Michal

    Brno : Ústav biologie obratlovců AVČR, 2011 - (Bryja, J.; Řehák, Z.; Zukal, J.). s. 25-26 ISBN 978-80-87189-09-2. [Zoologické dny. 17.02.2011-18.02.2011, Brno] Institutional research plan: CEZ:AV0Z60930519 Keywords : toll-like receptors * passerines Subject RIV: EG - Zoology http://zoo.ivb.cz/doc/sborniky/sbornik_2011.pdf

  6. Chapter 1. Overview of Toll-like receptors (TLRs) in the CNS

    Kielian, Tammy

    2009-01-01

    Mammalian Toll-like receptors (TLRs) were first identified in 1997 based on their homology with Drosophila Toll, which mediates innate immunity in the fly. Over the past 8 years, the number of manuscripts describing TLR expression and function in the central nervous system (CNS) has been increasing steadily and expanding beyond their traditional roles in infectious diseases to neurodegenerative disorders and injury. Interest in the field serves as the impetus for this volume in the Current To...

  7. Toll-like receptors as developmental tools that regulate neurogenesis during development: an update

    Barak, Boaz; Feldman, Noa; Okun, Eitan

    2014-01-01

    Neurogenesis, the process of generating new neurons in the brain, fascinates researchers for its promise to affect multiple cognitive and functional processes in both health and disease. Many cellular pathways are involved in the regulation of neurogenesis, a complexity exemplified by the extensive regulation of this process during brain development. Toll-like receptors (TLRs), hallmarks of innate immunity, are increasingly implemented in various central nervous system plasticity-related proc...

  8. Toll-like receptors as developmental tools that regulate neurogenesis during development: an update

    EitanOkun; BoazBarak

    2014-01-01

    Neurogenesis, the process of generating new neurons in the brain, fascinates researchers for its promise to affect multiple cognitive and functional processes in both health and disease. Many cellular pathways are involved in the regulation of neurogenesis, a complexity exemplified by the extensive regulation of this process during brain development. Toll-like receptors (TLRs), hallmarks of innate immunity are increasingly implemented in various central nervous system plasticity-related proce...

  9. Toll-like receptors as transducer of inflammatory signals in glia: the astrocyte-microglia connection

    Marinelli, Carla

    2015-01-01

    In physiological conditions glia in the central nervous system (CNS) can produce and release protective factors such as anti-oxidant molecules and neurotrophic factors (Sofroniew et al., 2010). Events that impinge on CNS homeostatic balance can induce local inflammatory responses (Carson et al., 2006). Reactive glia can participate producing pro-inflammatory mediators such as chemokines, cytokines, purines and free radicals. Toll-like receptors (TLRs) are involved in injury responses of n...

  10. Identification of Toll-like receptor genes in Grey Partridge (Perdix perdix)

    Tomášek, Oldřich; Vinkler, Michal; Bainová, H.; Opatová, Pavlína; Bryjová, Anna; Svobodová, J.; Albrecht, Tomáš

    Brno: Ústav biologie obratlovců AVČR, 2011 - (Bryja, J.; Řehák, Z.; Zukal, J.). s. 231-232 ISBN 978-80-87189-09-2. [Zoologické dny. 17.02.2011-18.02.2011, Brno] Institutional research plan: CEZ:AV0Z60930519 Keywords : Grey Partridge * Toll-like receptor Subject RIV: EG - Zoology http://zoo.ivb.cz/doc/sborniky/sbornik_2011.pdf

  11. The role of toll-like receptor variants in acute anterior uveitis

    Pratap, Divya S.; Lyndell L Lim; Wang, Jie Jin; Mackey, David A.; Kearns, Lisa S.; Stawell, Richard J.; ,; Kathryn P Burdon; Mitchell, Paul; Craig, Jamie E; Hall, Anthony J.; Hewitt, Alex W

    2011-01-01

    Purpose Acute anterior uveitis (AAU) is the most common form of uveitis; however, while it is presumed to have an immunological basis, the precise underlying etiology remains elusive. Toll-like receptors (TLRs) have a key role in linking innate and adaptive immunity, thereby forming a molecular bridge between microbial triggers and the development of AAU. The purpose of this study was to investigate the role of TLR2 and TLR4 gene polymorphisms in the pathogenesis of AAU. Methods The study com...

  12. Expression of Toll-like receptors 7-10 in human fallopian tubes

    Nasrin Ghasemi; Fatemehsadat Amjadi; Ensieh Salehi; Mojgan Shakeri; Abbas Aflatoonian; Reza Aflatoonian

    2014-01-01

    Background: The human female reproductive tract (FRT) is constantly deal with the invading pathogens. Recognition of these pathogens is attributed to the family of Toll like receptors (TLR) as a major part of the innate immune system. We and others have previously revealed that TLRs1-6 express in the female reproductive tract. However, more studies should be done to detect TLRs 7-10 in the female reproductive tract, especially in the fallopian tubes. Objective: To examine the expression of TL...

  13. Effects of human Toll-like receptor 1 polymorphisms on ageing

    Uciechowski Peter; Oellig Eva Maria; Mariani Erminia; Malavolta Marco; Mocchegiani Eugenio; Rink Lothar

    2013-01-01

    Abstract Background Advanced age results in crucial alterations of the innate and adaptive immune system leading to functional defects resulting in infection and chronic diseases. Toll-like receptors (TLR) recognize pathogenic structures and are important in the immune response to infections and vaccination. However, the role of TLR single nucleotide polymorphisms (SNP) is poorly understood in the setting of human ageing. This study investigated the impact of the TLR1 SNPs A743G and T1805G on...

  14. Everolimus-Eluting Stents Reduce Monocyte Expression of Toll-Like Receptor 4

    Mehriar Shokri; Bahador Bagheri; Alireza Garjani; Bahram Sohrabi; Afshin Habibzadeh; Babak Kazemi; Ali Akbar Movassaghpour

    2015-01-01

    Purpose: Toll-like receptors (TLR) are well known components of the innate immune system. Among them, TLR4 is related to the inflammatory processes involved in atherosclerotic plaque formation. Our purpose was to compare the monocytic expression of TLR4 following implantation of drug-eluting (DES) and bare stents (BMS). Methods: In this study, patients with chronic stable angina undergoing elective percutaneous coronary intervention (PCI) in ShahidMadani Heart Hospital, T...

  15. A conserved surface on Toll-like receptor 5 recognizes bacterial flagellin

    Andersen-Nissen, Erica; Smith, Kelly D.; Bonneau, Richard; Strong, Roland K.; Aderem, Alan

    2007-01-01

    The molecular basis for Toll-like receptor (TLR) recognition of microbial ligands is unknown. We demonstrate that mouse and human TLR5 discriminate between different flagellins, and we use this difference to map the flagellin recognition site on TLR5 to 228 amino acids of the extracellular domain. Through molecular modeling of the TLR5 ectodomain, we identify two conserved surface-exposed regions. Mutagenesis studies demonstrate that naturally occurring amino acid variation in TLR5 residue 26...

  16. Dependence of Bacterial Protein Adhesins on Toll-Like Receptors for Proinflammatory Cytokine Induction

    Hajishengallis, George; Martin, Michael; Sojar, Hakimuddin T.; Sharma, Ashu; Schifferle, Robert E.; DeNardin, Ernesto; Russell, Michael W.; Genco, Robert J.

    2002-01-01

    Toll-like receptors (TLRs) are important signal transducers that mediate inflammatory reactions induced by microbes through pattern recognition of virulence molecules such as lipopolysaccharide (LPS) and lipoproteins. We investigated whether proinflammatory cytokine responses induced by certain bacterial protein adhesins may also depend on TLRs. In differentiated THP-1 mononuclear cells stimulated by LPS-free recombinant fimbrillin (rFimA) from Porphyromonas gingivalis, cytokine release was a...

  17. Novel Toll-like receptor-4 deficiency attenuates trastuzumab (Herceptin) induced cardiac injury in mice

    Yousif Nasser; Al-amran Fadhil G

    2011-01-01

    Abstract Background Cardiac inflammation and generation of oxidative stress are known to contribute to trastuzumab (herceptin) induced cardiac toxicity. Toll-like receptors (TLRs) are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signaling, we investigated whether or not TLR4 is involved in trastuzumab induced cardiotoxicity. Methods Seven days after a single injection of herceptin (2 mg/kg; i.p.)...

  18. Discovery of toll-like receptor 13 exists in the teleost fish: Miiuy croaker (Perciformes, Sciaenidae).

    Wang, Yanjin; Bi, Xueyi; Chu, Qing; Xu, Tianjun

    2016-08-01

    Toll-like receptors (TLRs) play an indispensable role in the immune response for pathogen recognition and triggering not only innate immunity but also adaptive immunity. Here we report the TLR13 homologue, one member of TLRs, in Perciformes (especially Sciaenidae). And we used the miiuy croaker as represented species for further functional experiments. Former study reported the TLR13 only expressed in murine, and we are the first to report the teleost TLR13 (mmiTLR13). MmiTLR13 expressed highly in immune defense related tissues, such as the liver, spleen, and kidney, and Vibrio anguillarum or poly(I:C) infection showed the immune response of mmiTLR13. Further luciferase reporter assays showed the ability for activation of ISRE luciferase reporter, but it failed to active NF-κB. And further gene silence by short hairpin RNA (shRNA) confirmed the results. Immunofluorescence of mmiTLR13 presents the cytoplasmic distribution in Hela cell. In addition, the Toll/interleukin 1 receptor (TIR) domain of mammal TLR5 exhibits high identity with TLR13, which indicated the high homology between TLR5 and TLR13. These findings will lay the fundamental cornerstone for further research of teleost TLR13 and expand the horizon for better understand the teleost TLRs system. PMID:26952767

  19. Toll-like receptor cascade and gene polymorphism in host–pathogen interaction in Lyme disease

    Rahman, Shusmita; Shering, Maria; Ogden, Nicholas H; Lindsay, Robbin; Badawi, Alaa

    2016-01-01

    Lyme disease (LD) risk occurs in North America and Europe where the tick vectors of the causal agent Borrelia burgdorferi sensu lato are found. It is associated with local and systemic manifestations, and has persistent posttreatment health complications in some individuals. The innate immune system likely plays a critical role in both host defense against B. burgdorferi and disease severity. Recognition of B. burgdorferi, activation of the innate immune system, production of proinflammatory cytokines, and modulation of the host adaptive responses are all initiated by Toll-like receptors (TLRs). A number of Borrelia outer-surface proteins (eg, OspA and OspB) are recognized by TLRs. Specifically, TLR1 and TLR2 were identified as the receptors most relevant to LD. Several functional single-nucleotide polymorphisms have been identified in TLR genes, and are associated with varying cytokines types and synthesis levels, altered pathogen recognition, and disruption of the downstream signaling cascade. These single-nucleotide polymorphism-related functional alterations are postulated to be linked to disease development and posttreatment persistent illness. Elucidating the role of TLRs in LD may facilitate a better understanding of disease pathogenesis and can provide an insight into novel therapeutic targets during active disease or postinfection and posttreatment stages. PMID:27330321

  20. Molecular and cellular dynamics of the Toll-like receptor 4 pathway.

    Nick eGay

    2014-10-01

    Full Text Available As well as being the primary signaling receptor for bacterial endotoxin or lipopolysaccharide Toll-like receptor 4 function is modulated by numerous factors not only in the context of microbial pathogenesis but also autoimmune and allergic diseases. TLR4 is subject to multiple levels of endogenous control and regulation from biosynthesis and trafficking to signal transduction and degradation. On the other hand regulation of TLR4 activity breaks down during Gram –ve sepsis leading to systemic damage, multi organ failure and death. In this article we review how TLR4 traffics from the early secretory pathway, the cis/trans Golgi to the cell surface and endolysosomal compartments. We will present evidence about how these processes influence signaling and can potentially lead to ligand independent constitutive activation that may contribute to pathogenesis in sepsis. We will also discuss how sustained signaling may be coupled to endocytosis and consider the potential molecular mechanisms of immuno-modulators that modify TLR4 signalling function including the cat allergen FelD1 and endogenous protein ligands such as the extracellular matrix protein tenascin C and calprotectin (MRP8/14.

  1. DMPD: Inhibition of toll-like receptor and cytokine signaling--a unifying theme inischemic tolerance. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15545925 Inhibition of toll-like receptor and cytokine signaling--a unifying theme ...png) (.svg) (.html) (.csml) Show Inhibition of toll-like receptor and cytokine signaling--a unifying theme i...nischemic tolerance. PubmedID 15545925 Title Inhibition of toll-like receptor and

  2. DMPD: TICAM-1 and TICAM-2: toll-like receptor adapters that participate in inductionof type 1 interferons. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15618008 TICAM-1 and TICAM-2: toll-like receptor adapters that participate in induc... Mar;37(3):524-9. (.png) (.svg) (.html) (.csml) Show TICAM-1 and TICAM-2: toll-like receptor adapters that part... TICAM-2: toll-like receptor adapters that participate in inductionof type 1 interferons. Authors Seya T, Os

  3. DMPD: Toll-like receptors: from the discovery of NFkappaB to new insights intotranscriptional regulations in innate immunity. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 16930560 Toll-like receptors: from the discovery of NFkappaB to new insights intotr...2-13. Epub 2006 Aug 22. (.png) (.svg) (.html) (.csml) Show Toll-like receptors: from the discovery of NFkappaB to new...6930560 Title Toll-like receptors: from the discovery of NFkappaB to new insights intotranscriptional regula

  4. A new Vitreoscilla filiformis extract grown on spa water-enriched medium activates endogenous cutaneous antioxidant and antimicrobial defenses through a potential Toll-like receptor 2/protein kinase C, zeta transduction pathway

    Mahe YF

    2013-08-01

    Full Text Available Yann F Mahe,1 Marie-Jesus Perez,1 Charlotte Tacheau,1 Chantal Fanchon,2 Richard Martin,3 Françoise Rousset,1 Sophie Seite4 1L’Oreal Research and Innovation, Clichy, 2L’Oréal Research and Innovation, Chevilly Larue, 3L’Oréal Research and Innovation Tours, 4La Roche-Posay Pharmaceutical Laboratories, Asnières, France Abstract: Vitreoscilla filiformis (VF biomass (VFB has been widely used in cosmetic preparations and shown to modulate the major inducible free-radical scavenger mitochondrial superoxide dismutase in skin cells. By adding La Roche-Posay (LRP thermal spring water to the VF culture medium, we obtained a biomass (LRP-VFB with a similar mitochondrial superoxide dismutase activation capacity to VF. Also, the new biomass more powerfully stimulated mRNA expression and antimicrobial peptides in reconstructed epidermis. Interestingly, a predictive computer model that analyzed transducing events within skin epidermal cells suggested that this protective activity may involve the Toll-like receptor 2/protein kinase C, zeta transduction pathway. Protein kinase C, zeta inhibition was effectively shown to abolish VFB-induced gene stimulation and confirmed this hypothesis. This thus opens new avenues for investigation into the improvement of skin homeostatic defense in relation to the control of its physiological microbiota and innate immunity. Keywords: innate skin defenses, TLR2, PKCz, La Roche-Posay, mitochondrial superoxide dismutase, SOD2

  5. RNA Interference of Interferon Regulatory Factor-1 Gene Expression in THP-1 Cell Line Leads to Toll-Like Receptor-4 Overexpression/Activation As Well As Up-modulation of Annexin-II

    Christos I. Maratheftis

    2007-12-01

    Full Text Available Interferon regulatory factor-1 (IRF-1 is a candidate transcription factor for the regulation of the Toll-like receptor-4 (TLR-4 gene. Using a small interfering RNAbased (siRNA process to silence IRF-1 gene expression in the leukemic monocytic cell line THP-1, we investigated whether such a modulation would alter TLR-4 expression and activation status in these cells. The siIRF-1 cells expressed elevated levels of TLR-4 mRNA and protein compared to controls by 90% and 77%, respectively. ICAM.1 protein expression and apoptosis levels were increased by 8.35- and 4.25-fold, respectively. The siIRF-1 cells overexpressed Bax mRNA compared to controls. Proteomic analysis revealed upmodulation of the Annexin-II protein in siIRF-1 THP-1 cells. Myelodysplastic syndrome (MDS patients with an absence of full-length IRF-1 mRNA also overexpressed Annexin-II. It is plausible that this overexpression may lead to the activation of TLR-4 contributing to the increased apoptosis characterizing MDS.

  6. Role of Toll-like receptors in lung innate defense against invasive aspergillosis. Distinct impact in immunocompetent and immunocompromized hosts.

    Chignard, Michel; Balloy, Viviane; Sallenave, Jean-Michel; Si-Tahar, Mustapha

    2007-01-01

    Toll-like receptors are key to pathogen recognition by a host and to the subsequent triggering of an innate immune response. Experimental and clinical evidence shows that defects in Toll-like receptors or in signaling pathways downstream from these receptors render hosts susceptible to various types of infection, including aspergillosis. Patients receiving an immunosuppressive regimen, including corticosteroid therapy or cytotoxic chemotherapy, are also susceptible to infections. Aspergillus ...

  7. Emerging role of Toll-like receptors in the control of pain and itch

    Tong Liu; Yong-Jing Gao; Ru-Rong Ji

    2012-01-01

    Toll-like receptors (TLRs) are germline-encoded pattern-recognition receptors that initiate innate immune responses by recognizing molecular structures shared by a wide range of pathogens,known as pathogen-associated molecular patterns (PAMPs).After tissue injury or cellular stress,TLRs also detect endogenous ligands known as danger-associated molecular patterns (DAMPs).TLRs are expressed in both non-neuronal and neuronal cell types in the central nervous system (CNS) and contribute to both infectious and non-infectious disorders in the CNS.Following tissue insult and nerve injury,TLRs (such as TLR2,TLR3,and TLR4) induce the activation of microglia and astrocytes and the production of the proinflammatory cytokines in the spinal cord,leading to the development and maintenance of inflammatory pain and neuropathic pain.In particular,primary sensory neurons,such as nociceptors,express TLRs (e.g.,TLR4 and TLR7) to sense exogenous PAMPs and endogenous DAMPs released after tissue injury and cellular stress.These neuronal TLRs are new players in the processing of pain and itch by increasing the excitability of primary sensory neurons.Given the prevalence of chronic pain and itch and the suffering of affected people,insights into TLR signaling in the nervous system will open a new avenue for the management of clinical pain and itch.

  8. Role of Toll-like receptors in Helicobacter pylori infection and immunity.

    Smith, Sinéad M

    2014-08-15

    The gram-negative bacterium Helicobacter pylori (H. pylori) infects the stomachs of approximately half of the world's population. Although infection induces an immune response that contributes to chronic gastric inflammation, the response is not sufficient to eliminate the bacterium. H. pylori infection causes peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Disease outcome is linked to the severity of the host inflammatory response. Gastric epithelial cells represent the first line of innate immune defence against H. pylori, and respond to infection by initiating numerous cell signalling cascades, resulting in cytokine induction and the subsequent recruitment of inflammatory cells to the gastric mucosa. Pathogen recognition receptors of the Toll-like receptor (TLR) family mediate many of these cell signalling events. This review discusses recent findings on the role of various TLRs in the recognition of H. pylori in distinct cell types, describes the TLRs responsible for the recognition of individual H. pylori components and outlines the influence of innate immune activation on the subsequent development of the adaptive immune response. The mechanistic identification of host mediators of H. pylori-induced pathogenesis has the potential to reveal drug targets and opportunities for therapeutic intervention or prevention of H. pylori-associated disease by means of vaccines or immunomodulatory therapy. PMID:25133016

  9. Maternal endotoxin-induced fetal growth restriction in rats: Fetal responses in toll-like receptor

    Banun Kusumawardani

    2012-09-01

    Full Text Available Background: Porphyromonas gingivalis as a major etiology of periodontal disease can produce virulence factor, lipopolysaccharide/LPS, which is expected to play a role in the intrauterine fetal growth. Trophoblast at the maternal-fetal interface actively participates in response to infection through the expression of a family of natural immune receptors, toll-like receptor (TLR. Purpose: the aims of study were to identify endotoxin concentration in maternal blood serum of Porphyromonas gingivalis-infected pregnant rats, to characterize the TLR-4 expression in trophoblast cells, and to determine its effect on fetal growth. Methods: Female rats were infected with live-Porphyromonas gingivalis at concentration of 2 x 109 cells/ml into subgingival sulcus area of the maxillary first molar before and/or during pregnancy. They were sacrified on 14th and 20th gestational day. Fetuses were evaluated for weight and length. Endotoxin was detected by limulus amebocyte lysate assay in the maternal blood serum. The TLR-4 expression in trophoblast cells was detected by immunohistochemistry. Role of Toll-like receptors in health and diseases of gastrointestinal tract

    Greg Harris; Rhonda KuoLee; Wangxue Chen

    2006-01-01

    The human gastrointestinal (GI) tract is colonized by non-pathogenic commensal microflora and frequently exposed to many pathogenic organisms.For the maintenance of GI homeostasis, the host must discriminate between pathogenic and non-pathogenic organisms and initiate effective and appropriate immune and inflammatory responses. Mammalian toll-like receptors (TLRs) are members of the pattern-recognition receptor (PRR) family that plays a central role in the initiation of innate cellular immune responses and the subsequent adaptive immune responses to microbial pathogens. Recent studies have shown that gastrointestinal epithelial cells express almost all TLR subtypes characterized to date and that the expression and activation of TLRs in the GI tract are tightly and coordinately regulated. This review summarizes the current understanding of the crucial dual roles of TLRs in the development of host innate and adaptive immune responses to GI infections and the maintenance of the immune tolerance to commensal bacteria through down-regulation of surface expression of TLRs in intestinal epithelial cells.

  10. Role of Toll-like receptors in Helicobacter pylori infection and immunity

    Sinéad; M; Smith

    2014-01-01

    The gram-negative bacterium Helicobacter pylori(H. pylori) infects the stomachs of approximately half of the world’s population. Although infection induces an immune response that contributes to chronic gastric inflammation, the response is not sufficient to eliminate the bacterium. H. pylori infection causes peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Disease outcome is linked to the severity of the host inflammatory response. Gastric epithelial cells represent the first line of innate immune defence against H. pylori, and respond to infection by initiating numerous cell signalling cascades, resulting in cytokine induction and the subsequent recruitment of inflamma-tory cells to the gastric mucosa. Pathogen recognition receptors of the toll-like receptor(TLR) family mediate many of these cell signalling events. This review dis-cusses recent findings on the role of various TLRs in the recognition of H. pylori in distinct cell types, describes the TLRs responsible for the recognition of individual H. pylori components and outlines the influence of innate immune activation on the subsequent development of the adaptive immune response. The mechanistic iden-tification of host mediators of H. pylori-induced patho-genesis has the potential to reveal drug targets and opportunities for therapeutic intervention or prevention of H. pylori-associated disease by means of vaccines or immunomodulatory therapy.

  11. H1 antihistamines in allergic rhinitis: The molecular pathways of interleukin and toll - like receptor systems

    Jonny Karunia Fajar

    2016-03-01

    Full Text Available The complex interaction between inflammatory mediators in allergic rhinitis (AR is determined by the role of genetic polymorphisms, including interleukin (IL and toll-like receptor (TLR genes. This study aimed to discuss the effects of H1-antihistamines on IL and TLR systems. Several ILs involved in AR pathogenesis are: IL-4 (rs2243250, rs1800925, rs1801275, rs2227284, rs2070874, IL-6 (rs1800795, rs1800797, IL-10 (rs1800871, rs1800872, IL-12R (rs438421, IL-13 (rs1800925, rs20541, IL-17 (rs3819024, IL-18 (rs360721, rs360718, rs360717, rs187238, IL-23R (rs7517847, and IL-27 (rs153109, rs17855750. In the IL system, histamines stimulate the IL production in Type 2 helper T (Th2 cells through protein kinase A (PKA, janus kinase-signal transducer and activator of transcription (JAK-STAT pathway, and the activation of H1-histamine receptor and histidine decarboxylase (HDC genes. On contrary, antihistamines down-regulate the H1-histamine receptor gene expression through the transcription suppression of HDC and IL genes and suppress histamine basal signaling through the inverse agonistic activity. TLRs involved in AR pathogenesis are TLR2 (rs4696480, rs3804099, rs5743708, TLR4 (rs4986790, TLR6 (rs2381289, TLR7 (rs179008, rs5935438, TRL8 (rs2407992, rs5741883, rs17256081, rs4830805, rs3788935, rs178998, and TLR10 (rs11466651. In the TLR system, histamines trigger the TLR expression by stimulating interferon-γ (IFN-γ to up-regulate mast cells and by stimulating receptor-interacting protein (RIP to activate IκB kinase-β. Contrastingly, antihistamines suppress TIR-domain-containing adaptor protein inducing IFN-β (TRIF and RIP protein and thus inhibit the expression of TLR. In addition, several studies indicated that H1-antihistamines inhibit the IL and TLR systems indirectly.

  12. Bupleurum polysaccharides attenuates lipopolysaccharide-induced inflammation via modulating Toll-like receptor 4 signaling.

    Jian Wu

    Full Text Available BACKGROUND: Bupleurum polysaccharides (BPs, isolated from Bupleurum smithii var. parvifolium, possesses immunomodulatory activity, particularly on inflammation. Bacterial endotoxin lipopolysaccharide (LPS triggers innate immune responses through Toll-like receptor 4 (TLR4 on host cell membrane. The present study was performed to evaluate whether the therapeutic efficacy of BPs on suppression of LPS's pathogenecity could be associated with the modulating of TLR4 signaling pathway. METHODOLOGY/PRINCIPAL FINDINGS: LPS stimulated expression and activation of factors in the TLR4 signaling system, including TLR4, CD14, IRAK4, TRAF6, NF-κB, and JNK, determined using immunocytochemical and/or Western blot assays. BPs significantly inhibited these effects of LPS. LPS increased pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, IL-12p40, and IFN-β and NO production, evaluated using ELISA and Griess reaction assays, respectively. BPs antagonized these effects of LPS. Interestingly, BPs alone augmented secretion of some pro-inflammatory cytokines of non-LPS stimulated macrophages and enhanced phagocytic activity towards fluorescent E.coli bioparticles. In a rat model of acute lung injury (ALI with pulmonary hemorrhage and inflammation, BPs ameliorated lung injuries and suppressed TLR4 expression. SIGNIFICANCE: The therapeutic properties of BPs in alleviating inflammatory diseases could be attributed to its inhibitory effect on LPS-mediated TLR4 signaling.

  13. Oxidative stress augments toll-like receptor 8 mediated neutrophilic responses in healthy subjects

    Matsunaga Kazuto

    2009-06-01

    Full Text Available Abstract Background Excessive oxidative stress has been reported to be generated in inflamed tissues and contribute to the pathogenesis of inflammatory lung diseases, exacerbations of which induced by viral infections are associated with toll-like receptor (TLR activation. Among these receptors, TLR8 has been reported as a key receptor that recognizes single-strand RNA virus. However, it remains unknown whether TLR8 signaling is potentiated by oxidative stress. The aim of this study is to examine whether oxidative stress modulates TLR8 signaling in vitro. Methods Human peripheral blood neutrophils were obtained from healthy non-smokers and stimulated with TLR 7/8 agonist imidazoquinoline resiquimod (R848 in the presence or absence of hydrogen peroxide (H2O2. Neutrophilic responses including cytokine release, superoxide production and chemotaxis were examined, and the signal transduction was also analyzed. Results Activation of TLR8, but not TLR7, augmented IL-8 release. The R848-augmented IL-8 release was significantly potentiated by pretreatment with H2O2 (p L-cysteine reversed this potentiation. The combination of H2O2 and R848 significantly potentiated NF-kB phosphorylation and IkBα degradation. The H2O2-potentiated IL-8 release was suppressed by MG-132, a proteosome inhibitor, and by dexamethasone. The expressions of TLR8, myeloid differentiation primary response gene 88 (MyD88, and tumor necrosis factor receptor-associated factor 6 (TRAF6 were not affected by H2O2. Conclusion TLR8-mediated neutrophilic responses were markedly potentiated by oxidative stress, and the potentiation was mediated by enhanced NF-kB activation. These results suggest that oxidative stress might potentiate the neutrophilic inflammation during viral infection.

  14. Dynamic evolution of toll-like receptor multigene families in echinoderms.

    Buckley, Katherine M; Rast, Jonathan P

    2012-01-01

    The genome sequence of the purple sea urchin, Strongylocentrotus purpuratus, a large and long-lived invertebrate, provides a new perspective on animal immunity. Analysis of this genome uncovered a highly complex immune system in which the gene families that encode homologs of the pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR) sequences, more than 200 Nod-like receptors and 1095 scavenger receptor cysteine-rich domains, a 10-fold expansion relative to vertebrates. Given their stereotypic protein structure and simple intron-exon architecture, the TLRs are the most tractable of these families for more detailed analysis. A role for these receptors in immune defense is suggested by their similarity to TLRs in other organisms, sequence diversity, and expression in immunologically active tissues, including phagocytes. The complexity of the sea urchin TLR multigene families is largely derived from expansions independent of those in vertebrates and protostomes, although a small family of TLRs with structure similar to that of Drosophila Toll can be traced to an ancient eumetazoan ancestor. Several other echinoderm sequences are now available, including Lytechinus variegatus, as well as partial sequences from two other sea urchin species. Here, we present an analysis of the invertebrate deuterostome TLRs with emphasis on the echinoderms. Representatives of most of the S. purpuratus TLR subfamilies and homologs of the mccTLR sequences are found in L. variegatus, although the L. variegatus TLR gene family is notably smaller (68 TLR sequences). The phylogeny of these genes within sea urchins highlights lineage-specific expansions at higher resolution than is evident at the phylum level. These analyses identify quickly evolving TLR subfamilies that are likely to have novel immune recognition functions and other, more stable, subfamilies that may

  15. The herpes simplex virus 1-encoded envelope glycoprotein B activates NF-κB through the Toll-like receptor 2 and MyD88/TRAF6-dependent signaling pathway.

    Mingsheng Cai

    Full Text Available The innate immune response plays a critical role in the host defense against invading pathogens, and TLR2, a member of the Toll-like receptor (TLR family, has been implicated in the immune response and initiation of inflammatory cytokine secretion against several human viruses. Previous studies have demonstrated that infectious and ultraviolet-inactivated herpes simplex virus 1 (HSV-1 virions lead to the activation of nuclear factor kappa B (NF-κB and secretion of proinflammatory cytokines via TLR2. However, except for the envelope glycoprotein gH and gL, whether there are other determinants of HSV-1 responsible for TLR2 mediated biological effects is not known yet. Here, we demonstrated that the HSV-1-encoded envelope glycoprotein gB displays as molecular target recognized by TLR2. gB coimmunoprecipitated with TLR2, TLR1 and TLR6 in transfected and infected human embryonic kidney (HEK 293T cells. Treatment of TLR2-transfected HEK293T (HEK293T-TLR2 cells with purified gB results in the activation of NF-κB reporter, and this activation requires the recruitment of the adaptor molecules myeloid differentiation primary-response protein 88 (MyD88 and tumor necrosis factor receptor-associated factor 6 (TRAF6 but not CD14. Furthermore, activation of NF-κB was abrogated by anti-gB and anti-TLR2 blocking antibodies. In addition, the expression of interleukin-8 induced by gB was abrogated by the treatment of the human monocytic cell line THP-1 with anti-TLR2 blocking antibody or by the incubation of gB with anti-gB antibody. Taken together, these results indicate the importance and potency of HSV-1 gB as one of pathogen-associated molecular patterns (PAMPs molecule recognized by TLR2 with immediate kinetics.

  16. The emerging role of toll-like receptor pathways in surgical diseases.

    Romics, Laszlo Jr

    2012-02-03

    OBJECTIVE: To outline the emerging significance of Toll-like receptor (TLR) signaling pathways in surgical diseases. DATA SOURCES: A systematic review of the literature was undertaken by searching the MEDLINE database for the period 1966 to 2005 without language restriction. STUDY SELECTION: Original or review articles that described experimental data on the activation of TLR signaling pathways in surgically relevant diseases were selected for inclusion in this review. DATA EXTRACTION: Data were obtained from peer-reviewed articles and references. DATA SYNTHESIS: The role of TLRs in the recognition of pathogens renders them a key figure in the activation of both innate and adaptive immune responses during sepsis. However, emerging evidence points to fundamentally important roles in ulcerative colitis, Crohn disease, and Helicobacter pylori infection in the gastrointestinal tract and in the development of atherosclerotic plaques in the cardiovascular system. Furthermore, recent studies suggest that the regulation of the TLR pathway fulfills a central role in anticancer immunotherapy and in organ rejection after transplantation. CONCLUSION: Given the clinical significance of TLR pathways, the targeting of individual molecular components is likely to offer a broad range of future therapeutic modalities.

  17. DMPD: Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs andCTRPs. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17681884 Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs an...ng) (.svg) (.html) (.csml) Show Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs andC...TRPs. PubmedID 17681884 Title Adipose tissue as an immunological organ: Toll-like

  18. Phylogeny of Toll-like receptor signaling: adapting the innate response.

    Jeffrey M Roach

    Full Text Available The Toll-like receptors represent a largely evolutionarily conserved pathogen recognition machinery responsible for recognition of bacterial, fungal, protozoan, and viral pathogen associated microbial patterns and initiation of inflammatory response. Structurally the Toll-like receptors are comprised of an extracellular leucine rich repeat domain and a cytoplasmic Toll/Interleukin 1 receptor domain. Recognition takes place in the extracellular domain where as the cytoplasmic domain triggers a complex signal network required to sustain appropriate immune response. Signal transduction is regulated by the recruitment of different intracellular adaptors. The Toll-like receptors can be grouped depending on the usage of the adaptor, MyD88, into MyD88-dependent and MyD88 independent subsets. Herein, we present a unique phylogenetic analysis of domain regions of these receptors and their cognate signaling adaptor molecules. Although previously unclear from the phylogeny of full length receptors, these analyses indicate a separate evolutionary origin for the MyD88-dependent and MyD88-independent signaling pathway and provide evidence of a common ancestor for the vertebrate and invertebrate orthologs of the adaptor molecule MyD88. Together these observations suggest a very ancient origin of the MyD88-dependent pathway Additionally we show that early duplications gave rise to several adaptor molecule families. In some cases there is also strong pattern of parallel duplication between adaptor molecules and their corresponding TLR. Our results further support the hypothesis that phylogeny of specific domains involved in signaling pathway can shed light on key processes that link innate to adaptive immune response.

  19. Nerve Growth Factor Is Regulated by Toll-Like Receptor 2 in Human Intervertebral Discs.

    Krock, Emerson; Currie, J Brooke; Weber, Michael H; Ouellet, Jean A; Stone, Laura S; Rosenzweig, Derek H; Haglund, Lisbet

    2016-02-12

    Nerve growth factor (NGF) contributes to the development of chronic pain associated with degenerative connective tissue pathologies, such as intervertebral disc degeneration and osteoarthritis. However, surprisingly little is known about the regulation of NGF in these conditions. Toll-like receptors (TLR) are pattern recognition receptors classically associated with innate immunity but more recently were found to be activated by endogenous alarmins such as fragmented extracellular matrix proteins found in degenerating discs or cartilage. In this study we investigated if TLR activation regulates NGF and which signaling mechanisms control this response in intervertebral discs. TLR2 agonists, TLR4 agonists, or IL-1β (control) treatment increased NGF, brain-derived neurotrophic factor (BDNF), and IL-1β gene expression in human disc cells isolated from healthy, pain-free organ donors. However, only TLR2 activation or IL-1β treatment increased NGF protein secretion. TLR2 activation increased p38, ERK1/2, and p65 activity and increased p65 translocation to the cell nucleus. JNK activity was not affected by TLR2 activation. Inhibition of NF-κB, and to a lesser extent p38, but not ERK1/2 activity, blocked TLR2-driven NGF up-regulation at both the transcript and protein levels. These results provide a novel mechanism of NGF regulation in the intervertebral disc and potentially other pathogenic connective tissues. TLR2 and NF-κB signaling are known to increase cytokines and proteases, which accelerate matrix degradation. Therefore, TLR2 or NF-κB inhibition may both attenuate chronic pain and slow the degenerative progress in vivo. PMID:26668319

  1. Toll-like receptor 4 dependent responses to lung injury in a murine model of pulmonary contusion

    Hoth, J. Jason; Wells, Jonathan D.; Brownlee, Noel A.; Hiltbold, Elizabeth M.; Meredith, J Wayne; McCall, Charles E.; Yoza, Barbara K.

    2009-01-01

    Blunt chest trauma resulting in pulmonary contusion with an accompanying acute inflammatory response is a common but poorly understood injury. We previously demonstrated that toll-like receptor 2 participates in the inflammatory response to lung injury. We hypothesized that the toll-like receptor 4, in a MyD88-dependent manner, may also participate in the response to lung injury. To investigate this, we used a model of pulmonary contusion in the mouse that is similar to that observed clinical...

  2. A systematic review of CD14 and toll-like receptors in relation to asthma in Caucasian children

    Klaassen, Ester MM; Thönissen, Brenda EJT; van Eys, Guillaume; Dompeling, Edward; Jöbsis, Quirijn

    2013-01-01

    The aetiology of childhood asthma is complex. An early dysfunction in the immunological development of the innate immune system in combination with environmental factors possibly triggers asthma. CD14 and toll-like receptors are important components of the innate immune system. The aim of this systematic review was to obtain a better insight into the relation between CD14 and toll-like receptors and childhood asthma in Caucasians. We searched PubMed and EMBASE for relevant articles. In total,...

  3. Reduced expression of Toll-like receptor 4 inhibits human breast cancer cells proliferation and inflammatory cytokines secretion

    Xie Xiaofang; Wen Huiyan; Zhou Xiaoni; Feng Ping; Zhou Huiqin; Yang Huan; Shen Haiying; Zhu Xueming

    2010-01-01

    Abstract Background Tumor cell expression of Toll-like receptors (TLRs) can promote inflammation and cell survival in the tumor microenvironment. Toll-like receptor 4 (TLR4) signaling in tumor cells can mediate tumor cell immune escape and tumor progression, and it is regarded as one of the mechanisms for chronic inflammation in tumorigenesis and progression. The expression of TLR4 in human breast cancer cell line MDA-MB-231 and its biological function in the development and progression of br...

  4. In vitro inflammation inhibition model based on semi-continuous toll-like receptor biosensing.

    Jin-Woo Jeon

    Full Text Available A chemical inhibition model of inflammation is proposed by semi-continuous monitoring the density of toll-like receptor 1 (TLR1 expressed on mammalian cells following bacterial infection to investigate an in vivo-mimicked drug screening system. The inflammation was induced by adding bacterial lysate (e.g., Pseudomonas aeruginosa to a mammalian cell culture (e.g., A549 cell line. The TLR1 density on the same cells was immunochemically monitored up to three cycles under optimized cyclic bacterial stimulation-and-restoration conditions. The assay was carried out by adopting a cell-compatible immunoanalytical procedure and signal generation method. Signal intensity relative to the background control obtained without stimulation was employed to plot the standard curve for inflammation. To suppress the inflammatory response, sodium salicylate, which inhibits nuclear factor-κB activity, was used to prepare the standard curve for anti-inflammation. Such measurement of differential TLR densities was used as a biosensing approach discriminating the anti-inflammatory substance from the non-effector, which was simulated by using caffeic acid phenethyl ester and acetaminophen as the two components, respectively. As the same cells exposed to repetitive bacterial stimulation were semi-continuously monitored, the efficacy and toxicity of the inhibitors may further be determined regarding persistency against time. Therefore, this semi-continuous biosensing model could be appropriate as a substitute for animal-based experimentation during drug screening prior to pre-clinical tests.

  5. The complement system and toll-like receptors as integrated players in the pathophysiology of atherosclerosis.

    Hovland, Anders; Jonasson, Lena; Garred, Peter; Yndestad, Arne; Aukrust, Pål; Lappegård, Knut T; Espevik, Terje; Mollnes, Tom E

    2015-08-01

    Despite recent medical advances, atherosclerosis is a global burden accounting for numerous deaths and hospital admissions. Immune-mediated inflammation is a major component of the atherosclerotic process, but earlier research focus on adaptive immunity has gradually switched towards the role of innate immunity. The complement system and toll-like receptors (TLRs), and the crosstalk between them, may be of particular interest both with respect to pathogenesis and as therapeutic targets in atherosclerosis. Animal studies indicate that inhibition of C3a and C5a reduces atherosclerosis. In humans modified LDL-cholesterol activate complement and TLRs leading to downstream inflammation, and histopathological studies indicate that the innate immune system is present in atherosclerotic lesions. Moreover, clinical studies have demonstrated that both complement and TLRs are upregulated in atherosclerotic diseases, although interventional trials have this far been disappointing. However, based on recent research showing an intimate interplay between complement and TLRs we propose a model in which combined inhibition of both complement and TLRs may represent a potent anti-inflammatory therapeutic approach to reduce atherosclerosis. PMID:26086357

  6. Methemoglobin Is an Endogenous Toll-Like Receptor 4 Ligand—Relevance to Subarachnoid Hemorrhage

    Min Seong Kwon

    2015-03-01

    Full Text Available Neuroinflammation is a well-recognized consequence of subarachnoid hemorrhage (SAH, and may be responsible for important complications of SAH. Signaling by Toll-like receptor 4 (TLR4-mediated nuclear factor κB (NFκB in microglia plays a critical role in neuronal damage after SAH. Three molecules derived from erythrocyte breakdown have been postulated to be endogenous TLR4 ligands: methemoglobin (metHgb, heme and hemin. However, poor water solubility of heme and hemin, and lipopolysaccharide (LPS contamination have confounded our understanding of these molecules as endogenous TLR4 ligands. We used a 5-step process to obtain highly purified LPS-free metHgb, as confirmed by Fourier Transform Ion Cyclotron Resonance mass spectrometry and by the Limulus amebocyte lysate assay. Using this preparation, we show that metHgb is a TLR4 ligand at physiologically relevant concentrations. metHgb caused time- and dose-dependent secretion of the proinflammatory cytokine, tumor necrosis factor α (TNFα, from microglial and macrophage cell lines, with secretion inhibited by siRNA directed against TLR4, by the TLR4-specific inhibitors, Rs-LPS and TAK-242, and by anti-CD14 antibodies. Injection of purified LPS-free metHgb into the rat subarachnoid space induced microglial activation and TNFα upregulation. Together, our findings support the hypothesis that, following SAH, metHgb in the subarachnoid space can promote widespread TLR4-mediated neuroinflammation.

  7. Toll-Like Receptor 4 Engagement Mediates Prolyl Endopeptidase Release from Airway Epithelia via Exosomes.

    Szul, Tomasz; Bratcher, Preston E; Fraser, Kyle B; Kong, Michele; Tirouvanziam, Rabindra; Ingersoll, Sarah; Sztul, Elizabeth; Rangarajan, Sunil; Blalock, J Edwin; Xu, Xin; Gaggar, Amit

    2016-03-01

    Proteases are important regulators of pulmonary remodeling and airway inflammation. Recently, we have characterized the enzyme prolyl endopeptidase (PE), a serine peptidase, as a critical protease in the generation of the neutrophil chemoattractant tripeptide Pro-Gly-Pro (PGP) from collagen. However, PE has been characterized as a cytosolic enzyme, and the mechanism mediating PE release extracellularly remains unknown. We examined the role of exosomes derived from airway epithelia as a mechanism for PE release and the potential extracellular signals that regulate the release of these exosomes. We demonstrate a specific regulatory pathway of exosome release from airway epithelia and identify PE as novel exosome cargo. LPS stimulation of airway epithelial cells induces release of PE-containing exosomes, which is significantly attenuated by small interfering RNA depletion of Toll-like receptor 4 (TLR4). These differences were recapitulated upon intratracheal LPS administration in mice competent versus deficient for TLR4 signaling. Finally, sputum samples from subjects with cystic fibrosis colonized with Pseudomonas aeruginosa demonstrate elevated exosome content and increased PE levels. This TLR4-based mechanism highlights the first report of nonstochastic release of exosomes in the lung and couples TLR4 activation with matrikine generation. The increased quantity of these proteolytic exosomes in the airways of subjects with chronic lung disease highlights a new mechanism of injury and inflammation in the pathogenesis of pulmonary disorders. PMID:26222144

  8. Involvement of Toll-like receptors on Helicobacter pylori-induced immunity.

    Romy Käbisch

    Full Text Available Dendritic cells (DCs play a major role in the innate immune response since they recognize a broad repertoire of PAMPs mainly via Toll-like receptors (TLRs. During Helicobacter pylori (H. pylori infection, TLRs have been shown to be important to control cytokine response particularly in murine DCs. In the present study we analyzed the effect of blocking TLRs on human DCs. Co-incubation of human DCs with H. pylori resulted in the release of the pro-inflammatory cytokines IL-12p70, IL-6 and IL-10. Release of IL-12p70 and IL-10 was predominantly influenced when TLR4 signaling was blocked by adding specific antibodies, suggesting a strong influence on subsequent T cell responses through TLR4 activation on DCs. Co-incubation of H. pylori-primed DC with allogeneic CD4+ T cells resulted in the production of IFN-γ and IL-17A as well as the expression of Foxp3, validating a mixed Th1/Th17 and Treg response in vitro. Neutralization of TLR4 during H. pylori infection resulted in significantly decreased amounts of IL-17A and IFN-γ and reduced levels of Foxp3-expressing and IL-10-secreting T cells. Our findings suggest that DC cytokine secretion induced upon TLR4-mediated recognition of H. pylori influences inflammatory and regulatory T cell responses, which might facilitate the chronic bacterial persistence.

  9. Toll-like receptor-mediated immune response inhibits prion propagation.

    Kang, Sang-Gyun; Kim, Chiye; Cortez, Leonardo M; Carmen Garza, María; Yang, Jing; Wille, Holger; Sim, Valerie L; Westaway, David; McKenzie, Debbie; Aiken, Judd

    2016-06-01

    Prion diseases are progressive neurodegenerative disorders affecting humans and various mammals. The prominent neuropathological change in prion diseases is neuroinflammation characterized by activation of neuroglia surrounding prion deposition. The cause and effect of this cellular response, however, is unclear. We investigated innate immune defenses against prion infection using primary mixed neuronal and glial cultures. Conditional prion propagation occurred in glial cultures depending on their immune status. Preconditioning of the cells with the toll-like receptor (TLR) ligand, lipopolysaccharide, resulted in a reduction in prion propagation, whereas suppression of the immune responses with the synthetic glucocorticoid, dexamethasone, increased prion propagation. In response to recombinant prion fibrils, glial cells up-regulated TLRs (TLR1 and TLR2) expression and secreted cytokines (tumor necrosis factor-α, interleukin-1β, interleukin-6, granulocyte-macrophage colony-stimulating factor, and interferon-β). Preconditioning of neuronal and glial cultures with recombinant prion fibrils inhibited prion replication and altered microglial and astrocytic populations. Our results provide evidence that, in early stages of prion infection, glial cells respond to prion infection through TLR-mediated innate immunity. GLIA 2016;64:937-951. PMID:26880394

  10. Leptospiral lipopolysaccharide stimulates the expression of toll-like receptor 2 and cytokines in pig fibroblasts.

    Guo, Yijie; Fukuda, Tomokazu; Donai, Kenichiro; Kuroda, Kengo; Masuda, Mizuki; Nakamura, Shuichi; Yoneyama, Hiroshi; Isogai, Emiko

    2015-02-01

    Pigs throughout the world are afflicted with leptospirosis, causing serious economic losses and potential hazards to human health. Although it has been known that leptospiral lipopolysaccharide (L-LPS) is involved in an immunological reaction between an antigen and a host cell, little is known about how the immune system of pigs can respond to L-LPS. Here, we stimulated pig fibroblasts by L-LPS and then quantitatively measured gene and protein expression levels of two toll-like receptors (TLRs), TLR2 and TLR4, by real-time PCR and Western blotting. As a result, expression of TLR2 was found to be significantly up-regulated within 24 h after L-LPS stimulation whereas induction of TLR4 expression was relatively weak. We also revealed that of myeloid differentiation primary response gene 88 (MyD88), interleukin 6 (IL-6) and IL-8 gene expressions were markedly up-regulated by L-LPS stimulation. These results may suggest that the pig cell can activate TLR2 rather than TLR4 by L-LPS stimulation, thereby inducing expression of cytokines. PMID:25039909

  11. Dietary Saturated Fat Promotes Development of Hepatic Inflammation Through Toll-Like Receptor 4 in Mice.

    Sutter, Alton G; Palanisamy, Arun P; Lench, Julie H; Esckilsen, Scott; Geng, Tuoyu; Lewin, David N B; Cowart, Lauren A; Chavin, Kenneth D

    2016-07-01

    Nonalcoholic steatohepatitis (NASH) is currently the third most common cause of end stage liver disease necessitating transplantation. The question remains how inflammation and NASH develop in the setting of nonalcoholic fatty liver disease (NAFLD) and steatosis. Understand the roles of toll-like receptor 4 (TLR4) and dietary fats in the development of hepatic inflammation. Wild-type and TLR4 KO mice were fed a standard high fat diet (LD), a high saturated fat diet (MD), or an isocaloric control diet (CD). Sera and tissue were analyzed for development of hepatic steatosis, inflammation, and injury. MD induced features of hepatic steatosis and inflammation in wild-type, but not in TLR4 KO, mice. TLR4 KO prevented MD induced increases in NAFLD activity scores, serum alanine aminotransferase levels, and inflammatory cytokine expression. Inflammatory cell infiltration and cytokine expression were also lower in the TLR4 KO mice livers than wild-type mice fed MD. Hepatic expression of Collagen I transcripts and collagen deposition were also decreased in the TLR4 KO MD animals. Results show that TLR4 plays a critical role in the effects of dietary fat composition on the development of hepatic steatosis, inflammation, and injury consistent with nonalcoholic steatohepatitis. J. Cell. Biochem. 117: 1613-1621, 2016. © 2015 Wiley Periodicals, Inc. PMID:26600310

  12. Modulation of Female Genital Tract-Derived Dendritic Cell Migration and Activation in Response to Inflammatory Cytokines and Toll-Like Receptor Agonists.

    Muki S Shey

    Full Text Available HIV transmission across the genital mucosa is a major mode of new HIV infections in women. The probability of infection may be influenced by several factors including recruitment and activation of HIV target cells, such as dendritic cells (DCs and cytokine production, associated with genital inflammation. We evaluated the role of inflammatory cytokines and TLR signaling in migration and activation of genital tract DCs in the human cervical explant model. Hysterectomy tissues from 10 HIV-negative and 7 HIV-positive donor women were separated into ecto- and endocervical explants, and incubated with inflammatory cytokines (TNF-α, IL-1β, IL-8, MIP-1β or agonists for TLR4 (LPS, TLR2/1 (PAM3 and TLR7/8 (R848. Migration (frequency and activation (HLA-DR expression of myeloid and plasmacytoid DCs and Langerhans cells were measured by flow cytometry. We observed that cytokines, LPS and PAM3 induced activation of migrating myeloid and plasmacytoid DCs. LPS induced a 3.6 fold lower levels of migration of plasmacytoid DCs from HIV-infected women compared with HIV-uninfected women (median activation indices of 2.932 vs 0.833. There was however a 4.5 fold increase in migration of Langerhans cells in HIV-infected compared with HIV-uninfected women in response to cytokines (median activation indices of 3.539 vs 0.77. Only TLR agonists induced migration and activation of DCs from endocervical explants. Hormonal contraception use was associated with an increase in activation of DC subsets in the endo and ectocervical explants. We conclude that inflammatory signals in the female genital tract induced DC migration and activation, with possible important implications for HIV susceptibility of cervical tissues.

  13. Extracellular mtDNA activates NF-κB via toll-like receptor 9 and induces cell death in cardiomyocytes.

    Bliksøen, Marte; Mariero, Lars Henrik; Torp, May Kristin; Baysa, Anton; Ytrehus, Kirsti; Haugen, Fred; Seljeflot, Ingebjørg; Vaage, Jarle; Valen, Guro; Stensløkken, Kåre-Olav

    2016-07-01

    Acute myocardial infarction (AMI) causes sterile inflammation, which exacerbates tissue injury. Elevated levels of circulating mitochondrial DNA (mtDNA) have been associated with AMI. We hypothesized that mtDNA triggers an innate immune response via TLR9 and NF-κB activation, causing cardiomyocyte injury. Murine cardiomyocytes express TLR9 mRNA and protein and were able to internalize fluorescently labeled mouse mtDNA. Incubation of human embryonic kidney cells with serum from AMI patients containing naturally elevated levels of mtDNA induced TLR9-dependent NF-κB activity. This effect was mimicked by isolated mtDNA. mtDNA activated NF-κB in reporter mice both in vivo and in isolated cardiomyocytes. Moreover, incubation of isolated cardiomyocytes with mtDNA induced cell death after 4 and 24 h. Laser confocal microscopy showed that incubation of cardiomyocytes with mtDNA accelerated mitochondrial depolarization induced by reactive oxygen species. In contrast to mtDNA, isolated total DNA did not activate NF-κB nor induce cell death. In conclusion, mtDNA can induce TLR9-dependent NF-κB activation in reporter cells and activate NF-κB in cardiomyocytes. In cardiomyocytes, mtDNA causes mitochondrial dysfunction and death. Endogenous mtDNA in the extracellular space is a danger signal with direct detrimental effects on cardiomyocytes. PMID:27164906

  14. Heat shock protein 60 stimulates the migration of vascular smooth muscle cells via Toll-like receptor 4 and ERK MAPK activation

    Zhao, Ying; Zhang, Chenxu; Wei, Xuge; Li, Pei; Cui, Ying; Qin, Yuanhua; Wei, Xiaoqing; Jin, Minli; Kohama, Kazuhiro; Gao, Ying

    2015-01-01

    Accumulating evidence indicates that heat shock protein (HSP) 60 is strongly associated with the pathology of atherosclerosis (AS). However, the precise mechanisms by which HSP60 promotes atherosclerosis remain unclear. In the present study, we found that HSP60 mRNA and protein expression levels in the thoracic aorta are enhanced not only in a mouse model of AS but also in high-fat diet (HFD) mice. HSP60 expression and secretion was activated by platelet-derived growth factor-BB (PDGF-BB) and interleukin (IL)-8 in both human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (VSMCs). HSP60 was found to induce VSMC migration, and exposure to HSP60 activated ERK MAPK signaling. U0126, an inhibitor of ERK, reduced VSMC migration. The HSP60-stimulated VSMCs were found to express TLR4 mRNA but not TLR2 mRNA. Knockdown of TLR4 by siRNA reduced HSP60-induced VSMC migration and HSP60-induced ERK activation. Finally, HSP60 induced IL-8 secretion in VSMCs. Together these results suggest that HSP60 is involved in the stimulation of VSMC migration, via TLR4 and ERK MAPK activation. Meanwhile, activation of HSP60 is one of the most powerful methods of sending a ‘danger signal’ to the immune system to generate IL-8, which assists in the management of an infection or disease. PMID:26477505

  15. Heat shock protein 60 stimulates the migration of vascular smooth muscle cells via Toll-like receptor 4 and ERK MAPK activation

    Ying Zhao; Chenxu Zhang; Xuge Wei; Pei Li; Ying Cui; Yuanhua Qin; Xiaoqing Wei; Minli Jin; Kazuhiro Kohama; Ying Gao

    2015-01-01

    Accumulating evidence indicates that heat shock protein (HSP) 60 is strongly associated with the pathology of atherosclerosis (AS). However, the precise mechanisms by which HSP60 promotes atherosclerosis remain unclear. In the present study, we found that HSP60 mRNA and protein expression levels in the thoracic aorta are enhanced not only in a mouse model of AS but also in high-fat diet (HFD) mice. HSP60 expression and secretion was activated by platelet-derived growth factor-BB (PDGF-BB) and...

  16. Extracts of Feijoa Inhibit Toll-Like Receptor 2 Signaling and Activate Autophagy Implicating a Role in Dietary Control of IBD.

    Noha Ahmed Nasef

    Full Text Available Inflammatory bowel disease (IBD is a heterogeneous chronic inflammatory disease affecting the gut with limited treatment success for its sufferers. This suggests the need for better understanding of the different subtypes of the disease as well as nutritional interventions to compliment current treatments. In this study we assess the ability of a hydrophilic feijoa fraction (F3 to modulate autophagy a process known to regulate inflammation, via TLR2 using IBD cell lines.Mouse embryonic fibroblasts (MEF deleted for ATG5, and two intestinal epithelial cells HCT15 and HCT116, were used to test the anti-inflammatory effect of F3 after stimulating the cells with a TLR2 specific ligand PAM3CSK4.F3 was able to reduce TLR2 specific inflammation and stimulate autophagy in MEFs and HCT15 cells but not in HCT116 cells. The anti-inflammatory effect was reduced in the MEF cells deleted for ATG5. In addition, the activation of autophagy by F3 was enhanced by PAM3CSK4.F3 of feijoa can interact with cells via a TLR2 specific mechanism and reduce Nuclear factor kappa B (NF-κB activation in part due to stimulation of autophagy. These results suggest that there is potential benefit in using feijoa extracts as part of dietary interventions to manage IBD in patients.

  17. Toll-like receptor gene polymorphisms are associated with allergic rhinitis: a case control study

    Nilsson Daniel

    2012-08-01

    Full Text Available Abstract Background The Toll-like receptor proteins are important in host defense and initiation of the innate and adaptive immune responses. A number of studies have identified associations between genetic variation in the Toll-like receptor genes and allergic disorders such as asthma and allergic rhinitis. The present study aim to search for genetic variation associated with allergic rhinitis in the Toll-like receptor genes. Methods A first association analysis genotyped 73 SNPs in 182 cases and 378 controls from a Swedish population. Based on these results an additional 24 SNPs were analyzed in one Swedish population with 352 cases and 709 controls and one Chinese population with 948 cases and 580 controls. Results The first association analysis identified 4 allergic rhinitis-associated SNPs in the TLR7-TLR8 gene region. Subsequent analysis of 24 SNPs from this region identified 7 and 5 significant SNPs from the Swedish and Chinese populations, respectively. The corresponding risk-associated haplotypes are significant after Bonferroni correction and are the most common haplotypes in both populations. The associations are primarily detected in females in the Swedish population, whereas it is seen in males in the Chinese population. Further independent support for the involvement of this region in allergic rhinitis was obtained from quantitative skin prick test data generated in both populations. Conclusions Haplotypes in the TLR7-TLR8 gene region were associated with allergic rhinitis in one Swedish and one Chinese population. Since this region has earlier been associated with asthma and allergic rhinitis in a Danish linkage study this speaks strongly in favour of this region being truly involved in the development of this disease.

  18. Toll-like receptors on human mesenchymal stem cells drive their migration and immunomodulating responses.

    Tomchuck, Suzanne L; Zwezdaryk, Kevin J; Coffelt, Seth B; Waterman, Ruth S; Danka, Elizabeth S; Scandurro, Aline B

    2008-01-01

    Adult human bone marrow-derived mesenchymal stem cells (hMSCs) are under study as therapeutic delivery agents that assist in the repair of damaged tissues. To achieve the desired clinical outcomes for this strategy requires a better understanding of the mechanisms that drive the recruitment, migration, and engraftment of hMSCs to the targeted tissues. It is known that hMSCs are recruited to sites of stress or inflammation to fulfill their repair function. It is recognized that toll-like receptors (TLRs) mediate stress responses of other bone marrow-derived cells. This study explored the role of TLRs in mediating stress responses of hMSCs. Accordingly, the presence of TLRs in hMSCs was initially established by reverse transcription-polymerase chain reaction assays. Flow cytometry and fluorescence immunocytochemical analyses confirmed these findings. The stimulation of hMSCs with TLR agonists led to the activation of downstream signaling pathways, including nuclear factor kappaB, AKT, and MAPK. Consequently, activation of these pathways triggered the induction and secretion of cytokines, chemokines, and related TLR gene products as established from cDNA array, immunoassay, and cytokine antibody array analyses. Interestingly, the unique patterns of affected genes, cytokines, and chemokines measured identify these receptors as critical players in the clinically established immunomodulation observed for hMSCs. Lastly, hMSC migration was promoted by TLR ligand exposure as demonstrated by transwell migration assays. Conversely, disruption of TLRs by neutralizing TLR antibodies compromised hMSC migration. This study defines a novel TLR-driven stress and immune modulating response for hMSCs that is critical to consider in the design of stem cell-based therapies. PMID:17916800

  19. Virtual Screening Approaches towards the Discovery of Toll-Like Receptor Modulators

    Lucía Pérez-Regidor

    2016-09-01

    Full Text Available This review aims to summarize the latest efforts performed in the search for novel chemical entities such as Toll-like receptor (TLR modulators by means of virtual screening techniques. This is an emergent research field with only very recent (and successful contributions. Identification of drug-like molecules with potential therapeutic applications for the treatment of a variety of TLR-regulated diseases has attracted considerable interest due to the clinical potential. Additionally, the virtual screening databases and computational tools employed have been overviewed in a descriptive way, widening the scope for researchers interested in the field.

  20. Betaine inhibits Toll-like receptor 4 expression in rats with ethanol-induced liver injury

    2010-01-01

    AIM:To test whether ethanol feeding could induce Toll-like receptor 4(TLR4)responses,assess the hepatoprotective effect of betaine and its inhibitive effect on TLR4 in animal models of alcoholic liver injury.METHODS:Forty-eight female Sprague-Dawley rats were randomly divided into four groups as control,model,low and high dose betaine groups.Except control group,all rats were fed with high fat-containing diet plus ethanol and fish oil gavages for 8 wk.Betaine was administered intragastrically after exposure...

  1. The complement system and toll-like receptors as integrated players in the pathophysiology of atherosclerosis

    Hovland, Anders; Jonasson, Lena; Garred, Peter;

    2015-01-01

    innate immunity. The complement system and toll-like receptors (TLRs), and the crosstalk between them, may be of particular interest both with respect to pathogenesis and as therapeutic targets in atherosclerosis. Animal studies indicate that inhibition of C3a and C5a reduces atherosclerosis. In humans......Despite recent medical advances, atherosclerosis is a global burden accounting for numerous deaths and hospital admissions. Immune-mediated inflammation is a major component of the atherosclerotic process, but earlier research focus on adaptive immunity has gradually switched towards the role of...

  2. Genetic diversity of Toll-like receptor 5 among pig populations

    Xiuqin Yang; Haitao Li; Qingzhi Guan; Di Liu

    2013-01-01

    The Toll-like receptor 5 (TLR5) recognizes flagellin of Gram-positive and -negative bacteria and plays an important role in the host defense system. Here, we surveyed single nucleotide polymorphisms (SNPs) in the coding sequence of the porcine TLR5 gene in 83 individuals from five pig breeds, these including Chinese local populations and Western commercial pig breeds. A total of 19 medium polymorphic SNPs (0.25 < PIC < 0.5) were identified, three of which were missense mutations that clustere...

  3. Structural characterisation of Toll-like receptor 1 (TLR1) and Toll-like receptor 6 (TLR6) in elephant and harbor seals.

    Woodman, Sally; Gibson, Amanda J; García, Ana Rubio; Contreras, Guillermo Sanchez; Rossen, John W; Werling, Dirk; Offord, Victoria

    2016-01-01

    Pinnipeds are a diverse clade of semi-aquatic mammals, which act as key indicators of ecosystem health. Their transition from land to marine environments provides a complex microbial milieu, making them vulnerable to both aquatic and terrestrial pathogens, thereby contributing to pinniped population decline. Indeed, viral pathogens such as influenza A virus and phocine distemper virus (PDV) have been identified as the cause of several of these mass mortality events. Furthermore, bacterial infection with mammalian Brucella sp. and methicillin-resistant Staphylococcus aureus strains have also been observed in marine mammals, posing further risk to both co-habiting endangered species and public health. During these disease outbreaks, mortality rates have varied amongst different pinniped species. Analyses of innate immune receptors at the host-pathogen interface have previously identified variants which may drive these species-specific responses. Through a combination of both sequence- and structure-based methods, this study characterises members of the Toll-like receptor (TLR) 1 superfamily from both harbour and elephant seals, identifying variations which will help us to understand these species-specific innate immune responses, potentially aiding the development of specific vaccine-adjuvants for these species. PMID:26827833

  4. Serine Lipids of Porphyromonas gingivalis Are Human and Mouse Toll-Like Receptor 2 Ligands

    Clark, Robert B.; Cervantes, Jorge L.; Maciejewski, Mark W.; Farrokhi, Vahid; Nemati, Reza; Yao, Xudong; Anstadt, Emily; Fujiwara, Mai; Wright, Kyle T.; Riddle, Caroline; La Vake, Carson J.; Salazar, Juan C.; Finegold, Sydney

    2013-01-01

    The total cellular lipids of Porphyromas gingivalis, a known periodontal pathogen, were previously shown to promote dendritic cell activation and inhibition of osteoblasts through engagement of Toll-like receptor 2 (TLR2). The purpose of the present investigation was to fractionate all lipids of P. gingivalis and define which lipid classes account for the TLR2 engagement, based on both in vitro human cell assays and in vivo studies in mice. Specific serine-containing lipids of P. gingivalis, called lipid 654 and lipid 430, were identified in specific high-performance liquid chromatography fractions as the TLR2-activating lipids. The structures of these lipids were defined using tandem mass spectrometry and nuclear magnetic resonance methods. In vitro, both lipid 654 and lipid 430 activated TLR2-expressing HEK cells, and this activation was inhibited by anti-TLR2 antibody. In contrast, TLR4-expressing HEK cells failed to be activated by either lipid 654 or lipid 430. Wild-type (WT) or TLR2-deficient (TLR2−/−) mice were injected with either lipid 654 or lipid 430, and the effects on serum levels of the chemokine CCL2 were measured 4 h later. Administration of either lipid 654 or lipid 430 to WT mice resulted in a significant increase in serum CCL2 levels; in contrast, the administration of lipid 654 or lipid 430 to TLR2−/− mice resulted in no increase in serum CCL2. These results thus identify a new class of TLR2 ligands that are produced by P. gingivalis that likely play a significant role in mediating inflammatory responses both at periodontal sites and, potentially, in other tissues where these lipids might accumulate. PMID:23836823

  5. Toll-Like Receptor 4 Is Essential in the Development of Abdominal Aortic Aneurysm.

    Chao-Han Lai

    Full Text Available Toll-like receptor (TLR family plays a key role in innate immunity and various inflammatory responses. TLR4, one of the well-characterized pattern-recognition receptors, can be activated by endogenous damage-associated molecular pattern molecules such as high mobility group box 1 (HMGB1 to sustain sterile inflammation. Evidence suggested that blockade of TLR4 signaling may confer protection against abdominal aortic aneurysm (AAA. Herein we aimed to obtain further insight into the mechanism by which TLR4 might promote aneurysm formation. Characterization of the CaCl2-induced AAA model in mice revealed that upregulation of TLR4 expression, localized predominantly to vascular smooth muscle cells (VSMCs, was followed by a late decline during a 28-day period of AAA development. In vitro, TLR4 expression was increased in VSMCs treated with HMGB1. Knockdown of TLR4 by siRNA attenuated HMGB1-enhanced production of proinflammatory cytokines, specifically interleukin-6 and monocyte chemoattractant protein-1 (MCP-1, and matrix-degrading matrix metalloproteinase (MMP-2 from VSMCs. In vivo, two different strains of TLR4-deficient (C57BL/10ScNJ and C3H/HeJ mice were resistant to CaCl2-induced AAA formation compared to their respective controls (C57BL/10ScSnJ and C3H/HeN. Knockout of TLR4 reduced interleukin-6 and MCP-1 levels and HMGB1 expression, attenuated macrophage accumulation, and eventually suppressed MMP production, elastin destruction and VSMC loss. Finally, human AAA exhibited higher TLR4 expression that was localized to VSMCs. These data suggest that TLR4 signaling contributes to AAA formation by promoting a proinflammatory status of VSMCs and by inducing proteinase release from VSMCs during aneurysm initiation and development.

  6. Fungal pathogens - a sweet and sour treat for toll-like receptors

    Christelle eBourgeois

    2012-11-01

    Full Text Available Hundred-thousands of fungal species are present in our environment, including normal colonizers that constitute part of the human microbiota. The homeostasis of host-fungus interactions encompasses efficient fungal sensing, tolerance at mucosal surfaces, as well as antifungal defenses. Decrease in host immune fitness or increase in fungal burden may favor pathologies, ranging from superficial mucocutaneous diseases to invasive life-threatening fungal infections. Toll-like receptors (TLRs are essential players in this balance, due to their ability to control both inflammatory and anti-inflammatory processes upon recognition of fungal-specific pathogen-associated molecular patterns (PAMPs. Certain members of the TLR family participate to the initial recognition of fungal PAMPs on the cell surface, as well as inside phagosomes of innate immune cells. Active signaling cascades in phagocytes ultimately enable fungus clearance and the release of cytokines that shape and instruct other innate immune cells and the adaptive immune system. Some TLRs cooperate with other pattern recognition receptors (e.g., C-type lectins, Galectins, thus allowing for a tailored immune response. The spatio-temporal and physiological contributions of individual TLRs in fungal infections remains ill-defined, although in humans, TLR gene polymorphisms have been linked to increased susceptibility to fungal infections. This review focuses entirely on the role of TLRs that control the host susceptibility to environmental fungi (e.g., Aspergillus, Cryptoccocus, Coccidoides, as well as to the most frequent human fungal pathogens represented by the commensal Candida species. The emerging roles of TLRs in modulating host tolerance to fungi, and the strategies that evolved in some of these fungi to evade or use TLR recognition to their advantage will also be discussed, as well as their potential suitability as targets in vaccine therapies.

  7. Induction of bacterial lipoprotein tolerance is associated with suppression of toll-like receptor 2 expression.

    Wang, Jiang Huai

    2012-02-03

    Tolerance to bacterial cell wall components including lipopolysaccharide (LPS) may represent an essential regulatory mechanism during bacterial infection. Two members of the Toll-like receptor (TLR) family, TLR2 and TLR4, recognize the specific pattern of bacterial cell wall components. TLR4 has been found to be responsible for LPS tolerance. However, the role of TLR2 in bacterial lipoprotein (BLP) tolerance and LPS tolerance is unclear. Pretreatment of human THP-1 monocytic cells with a synthetic bacterial lipopeptide induced tolerance to a second BLP challenge with diminished tumor necrosis factor-alpha and interleukin-6 production, termed BLP tolerance. Furthermore, BLP-tolerized THP-1 cells no longer responded to LPS stimulation, indicating a cross-tolerance to LPS. Induction of BLP tolerance was CD14-independent, as THP-1 cells that lack membrane-bound CD14 developed tolerance both in serum-free conditions and in the presence of a specific CD14 blocking monoclonal antibody (MEM-18). Pre-exposure of THP-1 cells to BLP suppressed mitogen-activated protein kinase phosphorylation and nuclear factor-kappaB activation in response to subsequent BLP and LPS stimulation, which is comparable with that found in LPS-tolerized cells, indicating that BLP tolerance and LPS tolerance may share similar intracellular pathways. However, BLP strongly enhanced TLR2 expression in non-tolerized THP-1 cells, whereas LPS stimulation had no effect. Furthermore, a specific TLR2 blocking monoclonal antibody (2392) attenuated BLP-induced, but not LPS-induced, tumor necrosis factor-alpha and interleukin-6 production, indicating BLP rather than LPS as a ligand for TLR2 engagement and activation. More importantly, pretreatment of THP-1 cells with BLP strongly inhibited TLR2 activation in response to subsequent BLP stimulation. In contrast, LPS tolerance did not prevent BLP-induced TLR2 overexpression. These results demonstrate that BLP tolerance develops through down-regulation of TLR2

  8. Intracellular expression of toll-like receptor 4 in neuroblastoma cells and their unresponsiveness to lipopolysaccharide

    Recently it has been reported that, toll-like receptors (TLRs) are expressed on a series of tumor cells, such as colon cancer, breast cancer, prostate cancer, melanoma and lung cancer. Although some cancer cells like melanoma cells are known to respond to lipopolysaccharide (LPS) via TLR4, not all cancer cells are positive for TLR4. There is little information on the expression and function of TLR4 in neuroblastoma cells. In this study, we investigated the expression of TLR4 in human neuroblastoma NB-1 cell line. Expression and localization of TLR4 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometric analysis, respectively. Activation of nuclear factor (NF)-κB by LPS was detected by degradation of IκB-α and NF-κB luciferase assay. Activation and expression of mitogen-activated protein (MAP) kinase and interferon regulatory factor (IRF)-3 was detected by immunoblot analysis. Human NB-1 neuroblastoma cells expressed intracellular form of TLR4, but not the cell surface form. Further, NB-1 cells express CD14, MD2 and MyD88, which are required for LPS response. However, LPS did not significantly induce NF-κB activation in NB-1 cells although it slightly degraded IκB-α. NB-1 cells expressed no IRF-3, which plays a pivotal role on the MyD88-independent pathway of LPS signaling. Collectively, NB-1 cells are capable to avoid their response to LPS. Although human NB-1 neuroblastoma cells possessed all the molecules required for LPS response, they did not respond to LPS. It might be responsible for intracellular expression of TLR4 or lack of IRF-3

  9. Intracellular expression of toll-like receptor 4 in neuroblastoma cells and their unresponsiveness to lipopolysaccharide

    Mori Isamu

    2006-12-01

    Full Text Available Abstract Background Recently it has been reported that, toll-like receptors (TLRs are expressed on a series of tumor cells, such as colon cancer, breast cancer, prostate cancer, melanoma and lung cancer. Although some cancer cells like melanoma cells are known to respond to lipopolysaccharide (LPS via TLR4, not all cancer cells are positive for TLR4. There is little information on the expression and function of TLR4 in neuroblastoma cells. In this study, we investigated the expression of TLR4 in human neuroblastoma NB-1 cell line. Methods Expression and localization of TLR4 were detected by reverse transcription-polymerase chain reaction (RT-PCR and flow cytometric analysis, respectively. Activation of nuclear factor (NF-κB by LPS was detected by degradation of IκB-α and NF-κB luciferase assay. Activation and expression of mitogen-activated protein (MAP kinase and interferon regulatory factor (IRF-3 was detected by immunoblot analysis. Results Human NB-1 neuroblastoma cells expressed intracellular form of TLR4, but not the cell surface form. Further, NB-1 cells express CD14, MD2 and MyD88, which are required for LPS response. However, LPS did not significantly induce NF-κB activation in NB-1 cells although it slightly degraded IκB-α. NB-1 cells expressed no IRF-3, which plays a pivotal role on the MyD88-independent pathway of LPS signaling. Collectively, NB-1 cells are capable to avoid their response to LPS. Conclusion Although human NB-1 neuroblastoma cells possessed all the molecules required for LPS response, they did not respond to LPS. It might be responsible for intracellular expression of TLR4 or lack of IRF-3.

  10. Anti-radiation damage effect of polyethylenimine as a toll-like receptor 5 targeted agonist

    A number of agents are now available for use in protecting against ionizing radiation. These radiation-protective agents, however, have many adverse effects. Efforts have been made to develop new radiation-protective agents for medical application. Here, we investigated whether a compound, polyethylenimine (PEI), which activates Toll-like receptor 5 (TLR5)-mediated NF-kB signaling pathways, could have an anti-radiation effect on a mouse model. First, a cell-based screening model for an agonist of TLR5-mediated NF-kB pathway was established and then validated by activation of TLR5-mediated NF-kB luciferase reporter activity with a known TLR5 agonist, flagellin. We found that PEI induced dose-dependent activation of the TLR5-mediated NF-kB pathway, indicating that PEI is indeed a TLR5 agonist. Furthermore, the anti-radiation effect of polyethylenimine was assessed using a γ-ray total body irradiation (TBI) mouse model. Compared with the irradiation control, both survival time and survival rate were significantly improved in mice that received either a low dose of polyethylenimine (P=0.019) or a high dose of polyethylenimine (P<0.001). We also observed a positive correlation between animal body weight and survival time in mice that received a low dose of polyethylenimine, a high dose of polyethylenimine and amifostine, over a period of 30 days, r=0.42 (P<0.02), 0.72 (P<0.0001) and 0.95 (P<0.0001), respectively, while a negative correlation between animal body weight and survival time was observed in the irradiation control (r=-0.89; P<0.0001). These results indicate that polyethylenimine is a new TLR5 agonist with potential application in offering protection for patients receiving radiotherapy or in radiation-related accidents. (author)

  11. A peptide tetramer Tk-tPN induces tolerance of cardiac allografting by conversion of type 1 to type 2 immune responses via the Toll-like receptor 2 signal-promoted activation of the MCP1 gene.

    Li, Zuoqing; Yang, Neng; Zhou, Ling; Gu, Peng; Wang, Hui; Zhou, Yun; Zhou, Peijun; Lu, Liming; Chou, Kuang-Yen

    2016-03-01

    The plant protein trichosanthin (Tk) and its derived peptide tetramer Tk-tPN have been shown to stimulate the type 2 immune responses for treating autoimmune disease. This work explores the possibility of using Tk-tPN as a non-toxic immunosuppressant to induce transplantation tolerance using the mechanisms by which T-cell-mediated immune responses are transferred from type 1 to type 2 through innate immunity-related pathways. Immunocytes and cytokine secretions involved in the mouse cardiac allografting model with Tk-tPN treatment were characterized. Identification of critical genes and analysis of their functions through Toll-like receptor (TLR) -initiated signalling and the possible epigenetic changes were performed. Mean survival times of the cardiac allografts were delayed from 7·7 ± 0·3 days (control) to 22·7 ± 3·9 days (P Gata3(+) ), together with a selective expansion of the IL-4/IL-10-producing CD8(+)  CD28(-) regulatory T-cell subset. A TLR2-initiated high expression of chemokine gene MCP1 was detectable simultaneously. Epigenetically Tk/Tk-tPN could also acetylate the histone H3K9 of MCP1 promoter to skew the immunity towards T helper type 2 responses. Tk/Tk-tPN is therefore capable of down-regulating the type 1 response-dominant rejection of cardiac allografts by evoking type 2 immunity through the activation of a TLR2-initiated signalling pathway and MCP1 gene to expand the IL-4/IL-10-secreting CD8(+)  CD28(-) regulatory T cells. Tk-tPN could be a promising novel immunosuppressant to induce tolerance in allotransplantation. PMID:26694804

  12. Ubiquitin-specific Protease 20 Regulates the Reciprocal Functions of β-Arrestin2 in Toll-like Receptor 4-promoted Nuclear Factor κB (NFκB) Activation.

    Jean-Charles, Pierre-Yves; Zhang, Lisheng; Wu, Jiao-Hui; Han, Sang-Oh; Brian, Leigh; Freedman, Neil J; Shenoy, Sudha K

    2016-04-01

    Toll-like receptor 4 (TLR4) promotes vascular inflammatory disorders such as neointimal hyperplasia and atherosclerosis. TLR4 triggers NFκB signaling through the ubiquitin ligase TRAF6 (tumor necrosis factor receptor-associated factor 6). TRAF6 activity can be impeded by deubiquitinating enzymes like ubiquitin-specific protease 20 (USP20), which can reverse TRAF6 autoubiquitination, and by association with the multifunctional adaptor protein β-arrestin2. Although β-arrestin2 effects on TRAF6 suggest an anti-inflammatory role, physiologic β-arrestin2 promotes inflammation in atherosclerosis and neointimal hyperplasia. We hypothesized that anti- and proinflammatory dimensions of β-arrestin2 activity could be dictated by β-arrestin2's ubiquitination status, which has been linked with its ability to scaffold and localize activated ERK1/2 to signalosomes. With purified proteins and in intact cells, our protein interaction studies showed that TRAF6/USP20 association and subsequent USP20-mediated TRAF6 deubiquitination were β-arrestin2-dependent. Generation of transgenic mice with smooth muscle cell-specific expression of either USP20 or its catalytically inactive mutant revealed anti-inflammatory effects of USP20in vivoandin vitro Carotid endothelial denudation showed that antagonizing smooth muscle cell USP20 activity increased NFκB activation and neointimal hyperplasia. We found that β-arrestin2 ubiquitination was promoted by TLR4 and reversed by USP20. The association of USP20 with β-arrestin2 was augmented when β-arrestin2 ubiquitination was prevented and reduced when β-arrestin2 ubiquitination was rendered constitutive. Constitutive β-arrestin2 ubiquitination also augmented NFκB activation. We infer that pro- and anti-inflammatory activities of β-arrestin2 are determined by β-arrestin2 ubiquitination and that changes in USP20 expression and/or activity can therefore regulate inflammatory responses, at least in part, by defining the ubiquitination

  13. Toll-Like Receptors and Tissue Remodeling: The Pro/Cons Recent Findings.

    Micera, Alessandra; Balzamino, Bijorn Omar; Di Zazzo, Antonio; Biamonte, Filippo; Sica, Gigliola; Bonini, Stefano

    2016-03-01

    The Toll-like Receptor (TLR) family ensures prompt response towards pathogens, protecting the host against infections, and guarantees a realistic balance between protective and detrimental activities. Multiple regulating mechanisms characterize TLR activity that is not limited to innate and adaptive antimicrobial immune responses, as observed in the inflammatory (either infective, allergic, or autoimmune) responses associated with tissue remodeling. Following the insult and the arise of inflammatory response, tissue remodeling takes place and might develop in fibrosis, depending on microenvironment as a result of imbalanced fibroblasts (FBs) and myofibroblasts (myoFBs) activation/survival. The process is driven by an epithelial-fibroblast-immune cell cross-talk. While the main FB function is the matrix metabolism for tissue homeostasis or repair, the myoFB differentiation represents a crucial step in attempting repair of injury. FBs/myoFBs provide more than structural support at site of injury, synthesizing and/or reacting to different cytokines, growth factors, neuromediators and soluble/lipid mediators. TLR-bearing FBs/myoFBs might contribute at the innate immune level, providing a second line of protection/defense as well as being a target/effector cell of tissue remodeling. TLRs might also interfere with acute inflammation as well as with established fibrosis, triggering structural/functional changes in agreement with the genetic background, the site of lesion, the entity of associated infection, the poor blood circulation or the pharmacological treatments, all together strictly influencing tissue repair/remodeling process. This review will focus on the recent findings on TLRs at launch and long-lasting tissue remodeling process, that strongly suggest TLRs as optional targets for future therapies. PMID:26248215

  14. Grancalcin (GCA) modulates Toll-like receptor 9 (TLR9) mediated signaling through its direct interaction with TLR9.

    Kim, Tae Whan; Hong, Seunghee; Talukder, Amjad H; Pascual, Virginia; Liu, Yong-Jun

    2016-03-01

    Toll-like receptors (TLRs) are playing important roles in stimulating the innate immune response and intensifying adaptive immune response against invading pathogens. Appropriate regulation of TLR activation is important to maintain a balance between preventing tumor activation and inhibiting autoimmunity. Toll-like receptor 9 (TLR9) senses microbial DNA in the endosomes of plasmacytoid dendritic cells and triggers myeloid differentiation primary response gene 88 (MyD88) dependent nuclear factor kappa B (NF-κB) pathways and type I interferon (IFN) responses. However, mechanisms of how TLR9 signals are mediated and which molecules are involved in controlling TLR9 functions remain poorly understood. Here, we report that penta EF-hand protein grancalcin (GCA) interacts and binds with TLR9 in a yeast two-hybrid system and an overexpression system. Using siRNA-mediated knockdown experiments, we also revealed that GCA positively regulates type I IFN production, cytokine/chemokine production through nuclear localization of interferon regulatory factor 7 (IRF7), NF-κB activation, and mitogen-activated protein kinase (MAPK) activation in plasmacytoid dendritic cells. Our results indicate that heterodimerization of GCA and TLR9 is important for TLR9-mediated downstream signaling and might serve to fine tune processes against viral infection. PMID:26648480

  15. Lack of Association between Toll Like Receptor-2 and Toll Like Receptor-4 Gene Polymorphisms and Other Feature in Iranian Asthmatics Patients.

    Hamid Bahrami

    2015-02-01

    Full Text Available Asthma as a chronic inflammatory airway disease is considered to be the most common chronic disease that is involving genetic and environmental factors. Toll like receptors (TLRs and other inflammatory mediators are important in modulation of inflammation. In this study, we evaluated the role of TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms in the asthma susceptibility, progress, control levels and lung functions in Iranian patients. On 99 asthmatic patients and 120 normal subjects, TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms were evaluated by PCR-RFLP method recruiting Msp1 and Nco1 restriction enzymes, respectively. IgE serum levels by ELISA technique were determined and asthma diagnosis, treatment and control levels were considered using standard schemes and criteria. Our results indicated that the genotype and allele frequencies of the TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms were not significantly different between control subjects and asthmatics and were not related to in asthma features such as IgE levels, asthma history and pulmonary factors. Wherease some previous studies indicated TLRs and their polymorphisms might have some role in asthma incidence and features, our data demonstrated that TLR2 Arg753Gln and TLR4 Asp299Gly gene variants were not risk factors for asthma or its features in Iranian patients. Genetic complexity, ethnicity, influence of other genes or polymorphisms may overcome these polymorphisms in our asthmatics.

  16. Prevention of hyperglycemia-induced myocardial apoptosis by gene silencing of Toll-like receptor-4

    Singh Manpreet

    2010-12-01

    Full Text Available Abstract Background Apoptosis is an early event involved in cardiomyopathy associated with diabetes mellitus. Toll-like receptor (TLR signaling triggers cell apoptosis through multiple mechanisms. Up-regulation of TLR4 expression has been shown in diabetic mice. This study aimed to delineate the role of TLR4 in myocardial apoptosis, and to block this process through gene silencing of TLR4 in the myocardia of diabetic mice. Methods Diabetes was induced in C57/BL6 mice by the injection of streptozotocin. Diabetic mice were treated with 50 μg of TLR4 siRNA or scrambled siRNA as control. Myocardial apoptosis was determined by TUNEL assay. Results After 7 days of hyperglycemia, the level of TLR4 mRNA in myocardial tissue was significantly elevated. Treatment of TLR4 siRNA knocked down gene expression as well as diminished its elevation in diabetic mice. Apoptosis was evident in cardiac tissues of diabetic mice as detected by a TUNEL assay. In contrast, treatment with TLR4 siRNA minimized apoptosis in myocardial tissues. Mechanistically, caspase-3 activation was significantly inhibited in mice that were treated with TLR4 siRNA, but not in mice treated with control siRNA. Additionally, gene silencing of TLR4 resulted in suppression of apoptotic cascades, such as Fas and caspase-3 gene expression. TLR4 deficiency resulted in inhibition of reactive oxygen species (ROS production and NADPH oxidase activity, suggesting suppression of hyperglycemia-induced apoptosis by TLR4 is associated with attenuation of oxidative stress to the cardiomyocytes. Conclusions In summary, we present novel evidence that TLR4 plays a critical role in cardiac apoptosis. This is the first demonstration of the prevention of cardiac apoptosis in diabetic mice through silencing of the TLR4 gene.

  17. The Toll-Like receptor adaptor TRIF contributes to otitis media pathogenesis and recovery

    Pak Kwang

    2009-08-01

    Full Text Available Abstract Background Toll-like receptor (TLR signalling is crucial for innate immune responses to infection. The involvement of TLRs in otitis media (OM, the most prevalent childhood disease in developed countries, has been implicated by studies in middle ear cell lines, by association studies of TLR-related gene polymorphisms, and by altered OM in mice bearing mutations in TLR genes. Activated TLRs signal via two alternative intracellular signaling molecules with differing effects; MyD88 (Myeloid differentiation primary response gene 88 inducing primarily interleukin expression and TRIF (Tir-domain-containing adaptor inducing interferon β mediating type I interferon (IFN expression. We tested the hypothesis that TRIF and type I IFN signaling play a role in OM, using a murine model of OM induced by non-typeable Haemophilus influenzae (NTHi. The ME inflammatory response to NTHi was examined in wild-type (WT and TRIF-/- mice by qPCR, gene microarray, histopathology and bacterial culture. Results Expression of TRIF mRNA was only modesty enhanced during OM, but both type I IFN signalling genes and type I IFN-inducible genes were significantly up-regulated in WT mice. TRIF-deficient mice showed reduced but more persistent mucosal hyperplasia and less leukocyte infiltration into the ME in response to NTHi infection than did WT animals. Viable bacteria could be cultured from MEs of TRIF-/- mice for much longer in the course of disease than was the case for middle ears of WT mice. Conclusion Our results demonstrate that activation of TRIF/type I IFN responses is important in both the pathogenesis and resolution of NTHi-induced OM.

  18. Association of bovine Toll-like receptor 4 with tick infestation rates and blood histamine concentration.

    Zhao, G; Yu, M; Cui, Q-W; Zhou, X; Zhang, J-C; Li, H-X; Qu, K-X; Wang, G-L; Huang, B-Z

    2013-01-01

    We investigated a possible association between bovine Toll-like receptor 4 (TLR4) and resistance to tick infestation in 103 cattle, including BMY cattle (1/2 Brahman, 1/4 Murray Grey, and 1/4 Yunnan Yellow cattle), Brahman, and Red Angus grazing on improved pasture. The tick infestation weight and number of Rhipicephalus microplus and the blood histamine concentration were measured and compared with those of 32 Chinese Holsteins and 30 Simmentals. A 228-bp fragment was amplified and sequenced to analyze the polymorphisms of the TLR4 gene. After SSCP and sequencing analysis, 4 SNPs, i.e., 535(A>C), 546(T>C), 605(T>A), and 618(G>C), were identified, corresponding to GenBank accession Nos. AY297041 and NW_003104150; the latter two SNPs caused Leu→Gln and Gln→His substitutions, respectively. Genotype AA was completely predominant in the Chinese Holstein and Simmental; genotypes AA and AB were detected in Red Angus, while genotypes AA, AB, BB, and BC were detected in Brahman and in BMY cattle. A negative correlation was identified between blood histamine concentration and number of tick infestation; in BMY cattle this negative association was significant. The tick infestation in cattle with genotype BB was significantly lower than in those with genotype AA. Blood histamine concentration in cattle with genotype BB was significantly higher than in those with genotype AA. The TLR4 gene mutation could affect the blood histamine level and activate the immune reaction after tick infestation. Allele B has potential as a molecular marker for tick-resistance originated from Zebu cattle for use in cattle breeding programs. PMID:23479166

  19. Role of Toll-like receptor 4 and human defensin 5 in primary endocervical epithelial cells

    MA Jing-mei; YANG Hui-xia

    2010-01-01

    Background Endocervical epithelial cells play early roles in the defense of upper female genital tract to pathogens. Toll-like receptors (TLRs) and human defensins (HD) have recently been identified as fundamental components of the innate immune responses to bacterial pathogens. We aimed to use in vitro model of human primary endocervical epithelial cells (HPECs) to investigate their roles in innate immune response of the endocervix.Methods TLR4 expression and distribution in HPECs and endocervix were investigated by immunofluorescence (IF). Cultured HPECs were divided into lipopolysaccharide (LPS) group which were treated by LPS for 0, 24 and 48 hours, and control group without treatment. At each time point, the levels of HD5, IL-6 and TNF-a in supernants were determined by ELISA. TLR4 and HD5 expressions of cells were detected by Western blotting simultaneously. HD5 expression pattern was also compared between the HeLa cell line and HPECs.Results Endocervix tissue surface and HPECs expressed TLR4. After incubated with LPS, HPECs expressed significantly higher levels of TLR4 than control group, especially after 24 hours (P <0.01), however decreased after 48 hours with a similar level of TLR4 expression compared with control group. LPS could upregulate the secretion of HD5, IL-6 and TNF-α in a time-dependent manner (24 hours: P <0.05; 48 hours: P <0.01, compared with control group). Intracellular HD5 expression levels decreased over time. HD5 expression patterns in HPECs were different from HeLa cell line.Conclusions To respond to LPS stimulation, HPECs may function in the mucosal immune defense through TLR4 activation and HD5 secretion. HPEC is considered a significant model for immunological study.

  20. Herpes simplex virus induces neural oxidative damage via microglial cell Toll-like receptor-2

    Little Morgan R

    2010-06-01

    Full Text Available Abstract Background Using a murine model of herpes simplex virus (HSV-1 encephalitis, our laboratory has determined that induction of proinflammatory mediators in response to viral infection is largely mediated through a Toll-like receptor-2 (TLR2-dependent mechanism. Published studies have shown that, like other inflammatory mediators, reactive oxygen species (ROS are generated during viral brain infection. It is increasingly clear that ROS are responsible for facilitating secondary tissue damage during central nervous system infection and may contribute to neurotoxicity associated with herpes encephalitis. Methods Purified microglial cell and mixed neural cell cultures were prepared from C57B/6 and TLR2-/- mice. Intracellular ROS production in cultured murine microglia was measured via 2', 7'-Dichlorofluorescin diacetate (DCFH-DA oxidation. An assay for 8-isoprostane, a marker of lipid peroxidation, was utilized to measure free radical-associated cellular damage. Mixed neural cultures obtained from β-actin promoter-luciferase transgenic mice were used to detect neurotoxicity induced by HSV-infected microglia. Results Stimulation with HSV-1 elevated intracellular ROS in wild-type microglial cell cultures, while TLR2-/- microglia displayed delayed and attenuated ROS production following viral infection. HSV-infected TLR2-/- microglia produced less neuronal oxidative damage to mixed neural cell cultures in comparison to HSV-infected wild-type microglia. Further, HSV-infected TLR2-/- microglia were found to be less cytotoxic to cultured neurons compared to HSV-infected wild-type microglia. These effects were associated with decreased activation of p38 MAPK and p42/p44 ERK in TLR2-/- mice. Conclusions These studies demonstrate the importance of microglial cell TLR2 in inducing oxidative stress and neuronal damage in response to viral infection.

  1. Bovine Viral Diarrhea Virus Type 2 Impairs Macrophage Responsiveness to Toll-Like Receptor Ligation with the Exception of Toll-Like Receptor 7.

    Schaut, Robert G; Ridpath, Julia F; Sacco, Randy E

    2016-01-01

    Bovine viral diarrhea virus (BVDV) is a member of the Flaviviridae family. BVDV isolates are classified into two biotypes based on the development of cytopathic (cp) or non-cytopathic (ncp) effects in epithelial cell culture. BVDV isolates are further separated into species, BVDV1 and 2, based on genetic differences. Symptoms of BVDV infection range from subclinical to severe, depending on strain virulence, and may involve multiple organ systems and induction of a generalized immunosuppression. During BVDV-induced immune suppression, macrophages, critical to innate immunity, may have altered pathogen recognition receptor (PRR) signaling, including signaling through toll-like receptors (TLRs). Comparison of BVDV 2 strains with different biotypes and virulence levels is valuable to determining if there are differences in host macrophage cellular responses between viral phenotypes. The current study demonstrates that cytopathic (cp), noncytopathic (ncp), high (hv) or low virulence (lv) BVDV2 infection of bovine monocyte-derived macrophages (MDMΦ) result in differential expression of pro-inflammatory cytokines compared to uninfected MDMΦ. A hallmark of cp BVDV2 infection is IL-6 production. In response to TLR2 or 4 ligation, as might be observed during secondary bacterial infection, cytokine secretion was markedly decreased in BVDV2-infected MDMΦ, compared to non-infected MDMΦ. Macrophages were hyporesponsive to viral TLR3 or TLR8 ligation. However, TLR7 stimulation of BVDV2-infected MDMΦ induced cytokine secretion, unlike results observed for other TLRs. Together, these data suggest that BVDV2 infection modulated mRNA responses and induced a suppression of proinflammatory cytokine protein responses to TLR ligation in MDMΦ with the exception of TLR7 ligation. It is likely that there are distinct differences in TLR pathways modulated following BVDV2 infection, which have implications for macrophage responses to secondary infections. PMID:27420479

  2. Role of toll-like receptors in acute gastrointestinal radiation syndrome

    Ionizing radiation induces various disorders according to the radiation sensitivity of each organ. Acute gastrointestinal radiation syndrome is a serious illness that is caused by exposure of gastrointestinal tract to high amounts of ionizing radiation in radiation accidents or radiation therapy in cancer treatment. Although the pathological mechanism have been well studied in human and animals, no effective treatments have been developed to date. The Toll-like receptor (TLR) family is one of the best-characterized families of innate immune receptors, which induce innate immune response against pathogen infection. However, contrary to their protective function, recent studies have suggested that immune responses triggered by TLRs play deleterious roles by aggravating tissue inflammation in some inflammatory and autoimmune diseases. This review describes recent advancement of our understanding of acute gastrointestinal radiation syndrome and the contributions of TLR to its pathological mechanisms. (author)

  3. Trypanosoma cruzi and its components as exogenous mediators of inflammation recognized through Toll-like receptors

    Ricardo T. Gazzinelli

    1992-01-01

    Full Text Available TRYPANOSOMA cruzi is the etiologic agent of Chagas' disease, a parasitic disease of enormous importance in Latin America. Herein we review the studies that revealed the receptors from innate immunity that are involved in the recognition of this protozoan parasite. We showed that the recognition of T. cruzi and its components occurs through Toll-like receptors (TLR 2/CD14. Further, we showed in vivo the importance of the myeloid differentiation factor (MyD88, an adapter protein essential for the function of TLRs, in determining the parasitemia and mortality rate of mice infected with T. cruzi. We also discuss the implications of these findings in the pathophysiology of Chagas' disease.

  4. Regulation of chemokine receptor by Toll-like receptor 2 is critical to neutrophil migration and resistance to polymicrobial sepsis

    Alves-Filho, Jose C.; Freitas, Andressa; Souto, Fabricio O.; Spiller, Fernando; Paula-Neto, Heitor; Silva, Joao S.; Gazzinelli, Ricardo T.; Teixeira, Mauro M.; Ferreira, Sergio H.; Cunha, Fernando Q.

    2009-01-01

    Patients with sepsis have a marked defect in neutrophil migration. Here we identify a key role of Toll-like receptor 2 (TLR2) in the regulation of neutrophil migration and resistance during polymicrobial sepsis. We found that the expression of the chemokine receptor CXCR2 was dramatically down-regulated in circulating neutrophils from WT mice with severe sepsis, which correlates with reduced chemotaxis to CXCL2 in vitro and impaired migration into an infectious focus in vivo. TLR2 deficiency ...

  5. Inhibition of Toll-Like Receptor 2-Mediated Interleukin-8 Production in Cystic Fibrosis Airway Epithelial Cells via the α7-Nicotinic Acetylcholine Receptor

    Shane J. O'Neill; McElvaney, Noel G; Wells, Robert J.; Hugh Ramsay; Greene, Catherine M

    2010-01-01

    Cystic Fibrosis (CF) is an inherited disorder characterised by chronic inflammation of the airways. The lung manifestations of CF include colonization with Pseudomonas aeruginosa and Staphylococcus aureus leading to neutrophil-dominated airway inflammation and tissue damage. Inflammation in the CF lung is initiated by microbial components which activate the innate immune response via Toll-like receptors (TLRs), increasing airway epithelial cell production of proinflammatory mediators such as ...

  6. Toll-like receptor 2 deficiency leads to delayed exacerbation of ischemic injury

    Bohacek Ivan

    2012-08-01

    Full Text Available Abstract Background Using a live imaging approach, we have previously shown that microglia activation after stroke is characterized by marked and long-term induction of the Toll-like receptor (TLR 2 biophotonic signals. However, the role of TLR2 (and potentially other TLRs beyond the acute innate immune response and as early neuroprotection against ischemic injury is not well understood. Methods TLR2−/− mice were subjected to transient middle cerebral artery occlusion followed by different reperfusion times. Analyses assessing microglial activation profile/innate immune response were performed using in situ hybridization, immunohistochemistry analysis, flow cytometry and inflammatory cytokine array. The effects of the TLR2 deficiency on the evolution of ischemic brain injury were analyzed using a cresyl violet staining of brain sections with appropriate lesion size estimation. Results Here we report that TLR2 deficiency markedly affects post-stroke immune response resulting in delayed exacerbation of the ischemic injury. The temporal analysis of the microglia/macrophage activation profiles in TLR2−/− mice and age-matched controls revealed reduced microglia/macrophage activation after stroke, reduced capacity of resident microglia to proliferate as well as decreased levels of monocyte chemotactic protein-1 (MCP-1 and consequently lower levels of CD45high/CD11b+ expressing cells as shown by flow cytometry analysis. Importantly, although acute ischemic lesions (24 to 72 h were smaller in TLR2−/− mice, the observed alterations in innate immune response were more pronounced at later time points (at day 7 after initial stroke, which finally resulted in delayed exacerbation of ischemic lesion leading to larger chronic infarctions as compared with wild-type mice. Moreover, our results revealed that TLR2 deficiency is associated with significant decrease in the levels of neurotrophic/anti-apoptotic factor Insulin-like growth factor-1 (IGF-1

  7. Modulation of Toll-like receptor signaling in innate immunity by natural products.

    Chen, Luxi; Yu, Jianhua

    2016-08-01

    For centuries, natural products and their derivatives have provided a rich source of compounds for the development of new immunotherapies in the treatment of human disease. Many of these compounds are currently undergoing clinical trials, particularly as anti-oxidative, anti-microbial, and anti-cancer agents. However, the function and mechanism of natural products in how they interact with our immune system has yet to be extensively explored. Natural immune modulators may provide the key to control and ultimately defeat disorders affecting the immune system. They can either up- or down-regulate the immune response with few undesired adverse effects. In this review, we summarize the recent advancements made in utilizing natural products for immunomodulation and their important molecular targets, members of the Toll-like receptor (TLR) family, in the innate immune system. PMID:26899347

  8. Diversity in the Toll-like receptor genes of the Tasmanian devil (Sarcophilus harrisii).

    Cui, Jian; Cheng, Yuanyuan; Belov, Katherine

    2015-03-01

    The Tasmanian devil is an endangered marsupial species that has survived several historical bottlenecks and now has low genetic diversity. Here we characterize the Toll-like receptor (TLR) genes and their diversity in the Tasmanian devil. TLRs are a key innate immune gene family found in all animals. Ten TLR genes were identified in the Tasmanian devil genome. Unusually low levels of diversity were found in 25 devils from across Tasmania. We found two alleles at TLR2, TLR3 and TLR6. The other seven genes were monomorphic. The insurance population, which safeguards the species from extinction, has successfully managed to capture all of these TLR alleles, but concerns remain for the long-term survival of this species. PMID:25563844

  9. Regulation of chemokine receptor by Toll-like receptor 2 is critical to neutrophil migration and resistance to polymicrobial sepsis

    Alves-Filho, Jose C.; Freitas, Andressa; Souto, Fabricio O.; Spiller, Fernando; Paula-Neto, Heitor; Silva, Joao S.; Gazzinelli, Ricardo T.; Teixeira, Mauro M.; Ferreira, Sergio H.; Cunha, Fernando Q.

    2009-01-01

    Patients with sepsis have a marked defect in neutrophil migration. Here we identify a key role of Toll-like receptor 2 (TLR2) in the regulation of neutrophil migration and resistance during polymicrobial sepsis. We found that the expression of the chemokine receptor CXCR2 was dramatically down-regulated in circulating neutrophils from WT mice with severe sepsis, which correlates with reduced chemotaxis to CXCL2 in vitro and impaired migration into an infectious focus in vivo. TLR2 deficiency prevented the down-regulation of CXCR2 and failure of neutrophil migration. Moreover, TLR2−/− mice exhibited higher bacterial clearance, lower serum inflammatory cytokines, and improved survival rate during severe sepsis compared with WT mice. In vitro, the TLR2 agonist lipoteichoic acid (LTA) down-regulated CXCR2 expression and markedly inhibited the neutrophil chemotaxis and actin polymerization induced by CXCL2. Moreover, neutrophils activated ex vivo by LTA and adoptively transferred into naïve WT recipient mice displayed a significantly reduced competence to migrate toward thioglycolate-induced peritonitis. Finally, LTA enhanced the expression of G protein–coupled receptor kinases 2 (GRK2) in neutrophils; increased expression of GRK2 was seen in blood neutrophils from WT mice, but not TLR2−/− mice, with severe sepsis. Our findings identify an unexpected detrimental role of TLR2 in polymicrobial sepsis and suggest that inhibition of TLR2 signaling may improve survival from sepsis. PMID:19234125

  10. Serine dipeptide lipids of Porphyromonas gingivalis inhibit osteoblast differentiation: Relationship to Toll-like receptor 2.

    Wang, Yu-Hsiung; Nemati, Reza; Anstadt, Emily; Liu, Yaling; Son, Young; Zhu, Qiang; Yao, Xudong; Clark, Robert B; Rowe, David W; Nichols, Frank C

    2015-12-01

    Porphyromonas gingivalis is a periodontal pathogen strongly associated with loss of attachment and supporting bone for teeth. We have previously shown that the total lipid extract of P. gingivalis inhibits osteoblast differentiation through engagement of Toll-like receptor 2 (TLR2) and that serine dipeptide lipids of P. gingivalis engage both mouse and human TLR2. The purpose of the present investigation was to determine whether these serine lipids inhibit osteoblast differentiation in vitro and in vivo and whether TLR2 engagement is involved. Osteoblasts were obtained from calvaria of wild type or TLR2 knockout mouse pups that also express the Col2.3GFP transgene. Two classes of serine dipeptide lipids, termed Lipid 654 and Lipid 430, were tested. Osteoblast differentiation was monitored by cell GFP fluorescence and osteoblast gene expression and osteoblast function was monitored as von Kossa stained mineral deposits. Osteoblast differentiation and function were evaluated in calvarial cell cultures maintained for 21 days. Lipid 654 significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation and this inhibition was dependent on TLR2 engagement. Lipid 430 also significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation but these effects were only partially attributed to engagement of TLR2. More importantly, Lipid 430 stimulated TNF-α and RANKL gene expression in wild type cells but not in TLR2 knockout cells. Finally, osteoblast cultures were observed to hydrolyze Lipid 654 to Lipid 430 and this likely occurs through elevated PLA2 activity in the cultured cells. In conclusion, our results show that serine dipeptide lipids of P. gingivalis inhibit osteoblast differentiation and function at least in part through engagement of TLR2. The Lipid 430 serine class also increased the expression of genes that could increase osteoclast activity. We conclude that Lipid 654 and Lipid 430 have the potential

  11. Potential of PEGylated Toll-Like Receptor 7 Ligands for Controlling Inflammation and Functional Changes in Mouse Models of Asthma and Silicosis

    Ferreira, Tatiana Paula Teixeira; Mariano, Lívia Lacerda; Ghilosso-Bortolini, Roberta; de Arantes, Ana Carolina Santos; Fernandes, Andrey Junior; Berni, Michelle; Cecchinato, Valentina; Uguccioni, Mariagrazia; Maj, Roberto; Barberis, Alcide; Silva, Patricia Machado Rodrigues e; Martins, Marco Aurélio

    2016-01-01

    Prior investigations show that signaling activation through pattern recognition receptors can directly impact a number of inflammatory lung diseases. While toll-like receptor (TLR) 7 agonists have raised interest for their ability to inhibit allergen-induced pathological changes in experimental asthma conditions, the putative benefit of this treatment is limited by adverse effects. Our aim was to evaluate the therapeutic potential of two PEGylated purine-like compounds, TMX-302 and TMX-306, c...

  12. Molecular characterization of 10 Toll-like receptor genes in goat

    Toll-like receptors (TLR) play crucial roles in activating the innate immune system. To date, 10 human and 13 mice TLR have been identified to belong to the mammalian TLR family. In this study, we have cloned partial CDs of goat TLR, TLR1, TLR2, TLR5 for about 2kb, and the rest for more than 1kb. The cloned sequences were aligned to the corresponding regions of the relevant human, bovine and equip cabalas nucleotide sequences. As shown in Table I there is at least 79% identity between the relevant human and goat TLR nucleotide sequences. The identity of each cloned goat TLR to equus caballus and bovine reference sequence ranges between 81% and 98%. Translation of goat TLR nucleotide sequences and alignment to the human, bovine and Equus caballus TLR protein showed 69-97% of the amino acid sequence is conserved among the species. A broad pattern of tissue expression was obtained for goat TLR mRNA in heart, liver, spleen, lung, kidney, lymph node, muscle and small intestine. TLR1 was found to be expressed in spleen and lung. Goat TLR2 were expressed in most tissues except muscle and small intestine. We detected TLR3 in the goat spleen and lung. TLR6 and TLR2 had similar expression patterns except in heart, while TLR2 was expressed but not TLR6. TLR7 was expressed in the liver, spleen and kidney. Expression of goat TLR8 was similar to TLR3, which is found in the spleen and lung. Analysis of TLR10 expression pattern in goat revealed that this gene only expressed in the spleen. All of goat TLR mRNA were expressed at reasonably high levels in the spleen that is a tissue with an organized immune compartment. This also agrees with human in where TLR are mostly expressed in the spleen. To determine the overall role of goat TLR in mammal TLR evolution, a phylogenetic analysis was performed among mammal TLR (human, mouse, dog, cat, Pan-troglodytes, Macaca mulatta, Gallus gallus, equus caballus, bovine, pig, Mus musculus and Rattus norvegicus and goat). Phylogenetic and

  13. The role of MAPK in CD4{sup +} T cells toll-like receptor 9-mediated signaling following HHV-6 infection

    Chi, Jing [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Wang, Fang [Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, Jiangsu Province (China); Li, Lingyun [Department of Developmental Genetics, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Feng, Dongju [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Qin, Jian [College of Foreign Languages, Hehai University, Nanjing 210029, Jiangsu Province (China); Xie, Fangyi; Zhou, Feng; Chen, Yun; Wang, Jinfeng [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Yao, Kun, E-mail: yaokun@njmu.edu.cn [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China)

    2012-01-05

    Human herpesvirus-6 (HHV-6) is an important immunosuppressive and immunomodulatory virus that primarily infects immune cells (mainly CD4{sup +} T cells) and strongly suppresses the proliferation of infected cells. Toll-like receptors are pattern-recognition receptors essential for the development of an appropriate innate immune defense against infection. To understand the role of CD4{sup +} T cells in the innate response to HHV-6 infection and the involvement of TLRs, we used an in vitro infection model and observed that the infection of CD4{sup +} T cells resulted in the activation of JNK/SAPK via up-regulation of toll-like receptor 9 (TLR9). Associated with JNK activation, annexin V-PI staining indicated that HHV-6A was a strong inducer of apoptosis. Apoptotic response associated cytokines, IL-6 and TNF-{alpha} also induced by HHV-6A infection.

  14. Comprehensive survey and genomic characterization of toll-like receptors in channel catfish, Ictalurus punctatus: identification of novel fish TLRs

    A comprehensive survey of channel catfish Toll-Like Receptors (TLRs) was undertaken following a genomic PCR approach based on degenerate primers. Twenty different TLRs were identified in channel catfish. Channel catfish TLR sequences were characterized by phylogenetic analysis based on their conserv...

  15. OXIDATIVE BURST MEDIATED BY TOLL LIKE RECEPTORS (TLR) AND CD14 ON AVIAN HETEROPHILS STIMULATED WITH BACTERIAL TOLL AGONISTS

    Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharide (LPS) and lipoteichoic acid (LTA), which are found in the cell walls of gram negative and gram-positive bacteria, respectively. This study was conducted to determine if TLRs are present on...

  16. Allelic variability in Toll-like receptor 1, 2, 4 and 6 in wild-derived mice (Mus musculus)

    Bainová, Zuzana; Fornůsková, Alena; Čížková, Dagmar; Bryja, Josef; Piálek, Jaroslav; Vinkler, Michal

    Tübingen: Eberhard Karls Universität Tübingen, 2011. s. 493. [Congress of the European Society for Evolutionary Biology ESEB /13./. 20.08.2011-25.08.2011, Tübingen] Institutional research plan: CEZ:AV0Z60930519 Keywords : mice * Toll-like receptor Subject RIV: EG - Zoology

  17. Evoluce Toll-like receptorů 4, 5 a 7 u ptáků ze skupiny Galloanserae

    Vinkler, M.; Bainová, H.; Bryja, Josef

    Brno: Ústav biologie obratlovců AV ČR, 2015 - (Bryja, J.; Řehák, Z.; Zukal, J.). s. 254-255 ISBN 978-80-87189-18-4. [Zoologické dny. 12.02.2015-13.02.2015, Brno] Institutional support: RVO:68081766 Keywords : Toll-like receptors * birds Subject RIV: EG - Zoology

  18. Structure and expression of TLR4 in zebra finch (Taeniopygia guttata), the first Toll-like receptor in passerine birds

    Vinkler, Michal; Bryjová, Anna; Albrecht, Tomáš; Bryja, Josef

    Barcelona: AOPC, 2008. P-240. [Annual Meeting of the Society for Molecular Biology and Evolution. 05.06.2008-08.06.2008, Barcelona] Institutional research plan: CEZ:AV0Z60930519 Keywords : zebra finch * toll-like receptors Subject RIV: EB - Genetics ; Molecular Biology http://www.aopc.es/abst/obtimpres.php?idAbst=991

  19. Single-nucleotide polymorphisms in the Toll-like receptor pathway increase susceptibility to infections in severely injured trauma patients

    M.W.G.A. Bronkhorst (Maarten); N.D.A. Boyé (Nicole); M.A.Z. Lomax (Miranda); R. Vossen (Rolf); J.F. Bakker (Jurriaan); P. Patka (Peter); E.M.M. van Lieshout (Esther)

    2013-01-01

    textabstractBackground: Sepsis and subsequent multiple-organ failure are the predominant causes of late mortality in trauma patients. Susceptibility and response to infection is, in part, heritable. Single-nucleotide polymorphisms (SNPs) in Toll-like receptor (TLR) and cluster of differentiation 14

  20. Toll-like receptors -2, -4 and CD14 in human intestinal mucosa from patients with inflammatory Bowel Disease (IBD)

    Frolová, Lenka; Drastich, P.; Klimešová, Klára; Rossmann, Pavel; Tlaskalová, Helena

    Prague : Verlag, 2006, s. 80-80. [Meeting of the European Mucosal Immunology Group /5./. Prague (CZ), 05.10.2006-07.10.2006] R&D Projects: GA ČR GD310/03/H147 Institutional research plan: CEZ:AV0Z50200510 Keywords : crohns disease * ulcerative colitis * toll-like receptors Subject RIV: EE - Microbiology, Virology

  1. GENES, IN ADDITION TO TOLL-LIKE RECEPTOR 2, PLAY A ROLE IN ANTIBACTERIAL DEFENSE TO STREPTOCOCCAL PNEUMONIA

    Streptococcus infection in human populations continues to be a major cause of morbidity and mortality. To evaluate the effect of genetic background and toll-like receptor 2 (TLR2) on antibacterial defense to streptococcal infection, eight genetically diverse strains of mic...

  2. The role of toll-like receptors 2 and 4 in the pathogenesis of feline pyometra.

    Jursza, E; Kowalewski, M P; Boos, A; Skarzynski, D J; Socha, P; Siemieniuch, M J

    2015-03-01

    Pyometra is the most common uterine disease in queens. To protect itself from infection, the female reproductive tract possesses several immune mechanisms that are based on germline-encoded pattern recognition receptors (toll-like receptors [TLRs]). The aim of our study was to examine endometrial immunolocalization of TLR2/4, study the influence of lipopolysaccharide (LPS) and tumor necrosis factor (TNF) α on messenger RNA expression of both receptors in pyometric queens, and compare these patterns between estrous cycling queens and those hormonally treated with medroxyprogesterone acetate (MPA). Thirty-six queens, ranging in age from 7 months to 11 years, were allocated into seven groups (anestrus, estrus, mid-diestrus and late diestrus, short-term and long-term hormonally treated queens, and pyometric queens). At the messenger RNA level, the real-time polymerase chain reaction was applied, whereas at the TLR2/4 protein level, the expression was tested by immunohistochemistry. In queens at estrus, gene expression of TLR2 was upregulated after stimulation of endometrial explants by TNF (P pyometra development. PMID:25481489

  3. Intrathecal siRNA against Toll-like receptor 4 reduces nociception in a rat model of neuropathic pain

    Fei-xiang Wu, Jin-jun Bian, Xue-rong Miao, Sheng-dong Huang, Xue-wu Xu, De-jun Gong, Yu-ming Sun, Zhi-jie Lu, Wei-feng Yu

    2010-01-01

    Full Text Available Background: Neuropathic pain is characterized by hyperalgesia, allodynia and spontaneous pain. It often occurs as a result of injury to peripheral nerves, dorsal root ganglions (DRG, spinal cord, or brain. Recent studies have suggested that Toll-like receptor 4 (TLR4 might play a role in neuropathic pain. Methodology/Principal Findings: In this study, we investigated the role of TLR4 in a rat chronic constriction injury (CCI model and explored the feasibility of treating neuropathic pain by inhibiting TLR4. Our results demonstrated that intrathecal siRNA-mediated suppression of TLR4 attenuated CCI-induced mechanical allodynia and thermal hyperalgesia through inhibiting the activation of NF-κB p65 and production of proinflammatory cytokines (e.g., TNF-α and IL-1β. Conclusions/Significance: These findings suggest that suppression of TLR4 mediated by intrathecally administered siRNA may be a new strategy for the treatment of neuropathic pain.

  4. Microglia are required for astroglial toll-like receptor 4 response and for optimal TLR2 and TLR3 response

    Holm, Thomas Hellesøe; Draeby, Dina; Owens, Trevor

    2012-01-01

    Within the central nervous system, astrocytes and microglia are the primary responders to endogenous ligands released upon injury and stress, as well as to infectious pathogens. Toll-like receptors (TLRs) are implicated in recognition of both types of stimulus. Whether astrocytes respond as...... to lipopolysaccharide, microglia exert their effect on astrocytes at least partially through release of soluble mediators that directly activate or facilitate astrocyte responses. Our findings underline the contribution of glial crosstalk in CNS responses to injury or inflammation. © 2012 Wiley...... strongly as microglia to TLR agonists remains contentious. In this study, we have rigorously purified astrocytes to determine their capacity for autonomous TLR response, in absence of microglia. We used flow cytometry and differential adhesion as well as a myeloid lineage-specific suicide gene to purify...

  5. DMPD: Toll-like receptors, RIG-I-like RNA helicases and the antiviral innate immuneresponse. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 17667934 Toll-like receptors, RIG-I-like RNA helicases and the antiviral innate immuneresponse...g) (.svg) (.html) (.csml) Show Toll-like receptors, RIG-I-like RNA helicases and the antiviral innate immuneresponse...nd the antiviral innate immuneresponse. Authors Thompson AJ, Locarnini SA. Publication Immunol Cell Biol. 20

  6. Toll-Like Receptor 4 Wild Type Homozygozity of Polymorphisms +896 and +1196 Is Associated with High Gastrin Serum Levels and Peptic Ulcer Risk.

    Vesa-Matti Pohjanen

    Full Text Available Toll-like receptor 4 is a part of the innate immune system and recognizes Helicobacter pylori lipopolysaccharide. The goal of this study was to analyze the role of Toll-like receptor 4 polymorphisms +896 (rs4986790 and +1196 (rs4986791 in the pathogenesis of Helicobacter pylori related gastroduodenal diseases in relation to gastric secretion and inflammation. Toll-like receptor 4 polymorphisms, serum gastrin-17 and pepsinogen I and II concentrations were determined, and gastroscopies with histopathological analyses were performed to 216 dyspeptic patients. As genotype controls, 179 controls and 61 gastric cancer patients were studied. In our study, the Toll-like receptor 4 +896 and +1196 polymorphisms were in total linkage disequilibrium. The homozygous wild types displayed higher gastrin-17 serum concentrations than the mutants (p = 0.001 and this effect was independent of Helicobacter pylori. The homozygous wild types also displayed an increased risk for peptic ulcers (OR: 4.390. Toll-like receptor 4 genotypes did not show any association with Helicobacter pylori positivity or the features of gastric inflammation. Toll-like receptor 4 expression was seen in gastrin and somatostatin expressing cells of antral mucosa by immunohistochemistry. Our results suggest a role for Toll-like receptor 4 in gastric acid regulation and that the Toll-like receptor 4 +896 and +1196 wild type homozygozity increases peptic ulcer risk via gastrin secretion.

  7. Toll-Like Receptor 4 Wild Type Homozygozity of Polymorphisms +896 and +1196 Is Associated with High Gastrin Serum Levels and Peptic Ulcer Risk

    Pohjanen, Vesa-Matti; Koivurova, Olli-Pekka; Huhta, Heikki; Helminen, Olli; Mäkinen, Johanna M.; Karhukorpi, Jari M.; Joensuu, Tapio; Koistinen, Pentti O.; Valtonen, Jarno M.; Niemelä, Seppo E.; Karttunen, Riitta A.; Karttunen, Tuomo J.

    2015-01-01

    Toll-like receptor 4 is a part of the innate immune system and recognizes Helicobacter pylori lipopolysaccharide. The goal of this study was to analyze the role of Toll-like receptor 4 polymorphisms +896 (rs4986790) and +1196 (rs4986791) in the pathogenesis of Helicobacter pylori related gastroduodenal diseases in relation to gastric secretion and inflammation. Toll-like receptor 4 polymorphisms, serum gastrin-17 and pepsinogen I and II concentrations were determined, and gastroscopies with histopathological analyses were performed to 216 dyspeptic patients. As genotype controls, 179 controls and 61 gastric cancer patients were studied. In our study, the Toll-like receptor 4 +896 and +1196 polymorphisms were in total linkage disequilibrium. The homozygous wild types displayed higher gastrin-17 serum concentrations than the mutants (p = 0.001) and this effect was independent of Helicobacter pylori. The homozygous wild types also displayed an increased risk for peptic ulcers (OR: 4.390). Toll-like receptor 4 genotypes did not show any association with Helicobacter pylori positivity or the features of gastric inflammation. Toll-like receptor 4 expression was seen in gastrin and somatostatin expressing cells of antral mucosa by immunohistochemistry. Our results suggest a role for Toll-like receptor 4 in gastric acid regulation and that the Toll-like receptor 4 +896 and +1196 wild type homozygozity increases peptic ulcer risk via gastrin secretion. PMID:26161647

  8. DMPD: Toll-like receptors and the host defense against microbial pathogens: bringingspecificity to the innate-immune system. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15075354 Toll-like receptors and the host defense against microbial pathogens: bringings... the host defense against microbial pathogens: bringingspecificity to the innate-...immune system. PubmedID 15075354 Title Toll-like receptors and the host defense against microbial pathogens: bringings

  9. Colorectal irradiation induced immune response: 'toll like receptors' therapeutic manipulation

    Exposure of the abdomino-pelvic sphere to ionizing radiation is associated with a high incidence of complications. Radiation therapy may cause short and / or long-term harmful effects. In the most severe cases and in the absence of heavy treatments, the appearance of ulcers may induce the death of patients. Clinical trials are being conducted with Mesenchymal Stem Cells (MSC) to cure theses complications. Others studies indicate that the injection of bacterial motifs limits the radiotoxicity in the intestine. They stimulate receptors (Toll-Like- Receptors (TLR)) located on the surface of epithelial and intestinal immune cells. The first aim of this doctoral work is to characterize the effects of TLR stimulation on immunity and tissue repair using a model of localized colorectal irradiation at 20 Gy (acute effects of radiotherapy) on a rat. The thesis then aims to potentiate the effects of the MSC treatment when adding TLR ligands upon localized colorectal irradiation at 27 Gy (accidental complications). This work, using a 20 Gy exposure, show that TLR stimulation improves homeostasis (normalization of T cells, induction of regulatory T cells (Treg) and macrophages 'anti-inflammatory' M2). On the 27 Gy colorectal model, the injection of TLR ligand before CSM transplant improves the immune climate by reducing pro-inflammatory cytokines and inducting Treg and M2 cells. These modulations could contribute to improving the implantation and effectiveness of CSM. The observations have all shown that the stimulation of immunity is an approach to minimize radiation-induced lesions. (author)

  10. The evolution of bat nucleic acid-sensing Toll-like receptors.

    Escalera-Zamudio, Marina; Zepeda-Mendoza, M Lisandra; Loza-Rubio, Elizabeth; Rojas-Anaya, Edith; Méndez-Ojeda, Maria L; Arias, Carlos F; Greenwood, Alex D

    2015-12-01

    We characterized the nucleic acid-sensing Toll-like receptors (TLR) of a New World bat species, the common vampire bat (Desmodus rotundus), and through a comparative molecular evolutionary approach searched for general adaptation patterns among the nucleic acid-sensing TLRs of eight different bats species belonging to three families (Pteropodidae, Vespertilionidae and Phyllostomidae). We found that the bat TLRs are evolving slowly and mostly under purifying selection and that the divergence pattern of such receptors is overall congruent with the species tree, consistent with the evolution of many other mammalian nuclear genes. However, the chiropteran TLRs exhibited unique mutations fixed in ligand-binding sites, some of which involved nonconservative amino acid changes and/or targets of positive selection. Such changes could potentially modify protein function and ligand-binding properties, as some changes were predicted to alter nucleic acid binding motifs in TLR 9. Moreover, evidence for episodic diversifying selection acting specifically upon the bat lineage and sublineages was detected. Thus, the long-term adaptation of chiropterans to a wide variety of environments and ecological niches with different pathogen profiles is likely to have shaped the evolution of the bat TLRs in an order-specific manner. The observed evolutionary patterns provide evidence for potential functional differences between bat and other mammalian TLRs in terms of resistance to specific pathogens or recognition of nucleic acids in general. PMID:26503258

  11. Macroscopic law of conservation revealed in the population dynamics of Toll-like receptor signaling

    Selvarajoo Kumar

    2011-04-01

    Full Text Available Abstract Stimulating the receptors of a single cell generates stochastic intracellular signaling. The fluctuating response has been attributed to the low abundance of signaling molecules and the spatio-temporal effects of diffusion and crowding. At population level, however, cells are able to execute well-defined deterministic biological processes such as growth, division, differentiation and immune response. These data reflect biology as a system possessing microscopic and macroscopic dynamics. This commentary discusses the average population response of the Toll-like receptor (TLR 3 and 4 signaling. Without requiring detailed experimental data, linear response equations together with the fundamental law of information conservation have been used to decipher novel network features such as unknown intermediates, processes and cross-talk mechanisms. For single cell response, however, such simplicity seems far from reality. Thus, as observed in any other complex systems, biology can be considered to possess order and disorder, inheriting a mixture of predictable population level and unpredictable single cell outcomes.

  12. Toll-Like Receptor-4 Dependent Small Intestinal Immune Responses Following Murine Arcobacter Butzleri Infection.

    Heimesaat, Markus M; Karadas, Gül; Fischer, André; Göbel, Ulf B; Alter, Thomas; Bereswill, Stefan; Gölz, Greta

    2015-12-01

    Sporadic cases of gastroenteritis have been attributed to Arcobacter butzleri infection, but information about the underlying immunopathological mechanisms is scarce. We have recently shown that experimental A. butzleri infection induces intestinal, extraintestinal and systemic immune responses in gnotobiotic IL-10(-/-) mice. The aim of the present study was to investigate the immunopathological role of Toll-like Receptor-4, the receptor for lipopolysaccharide and lipooligosaccharide of Gram-negative bacteria, during murine A. butzleri infection. To address this, gnotobiotic IL-10(-/-) mice lacking TLR-4 were generated by broad-spectrum antibiotic treatment and perorally infected with two different A. butzleri strains isolated from a patient (CCUG 30485) or fresh chicken meat (C1), respectively. Bacteria of either strain stably colonized the ilea of mice irrespective of their genotype at days 6 and 16 postinfection. As compared to IL-10(-/-) control animals, TLR-4(-/-) IL-10(-/-) mice were protected from A. butzleri-induced ileal apoptosis, from ileal influx of adaptive immune cells including T lymphocytes, regulatory T-cells and B lymphocytes, and from increased ileal IFN-γ secretion. Given that TLR-4-signaling is essential for A. butzleri-induced intestinal inflammation, we conclude that bacterial lipooligosaccharide or lipopolysaccharide compounds aggravate intestinal inflammation and may thus represent major virulence factors of Arcobacter. Future studies need to further unravel the molecular mechanisms of TLR-4-mediated A. butzleri-host interactions. PMID:26716022

  13. Are Toll-like receptor gene polymorphisms associated with prostate cancer?

    The suggestion that there is a connection between chronic intraprostatic inflammation and prostate cancer was declared some years ago. As Toll-like receptors (TLRs) are the key players in the processes of chronic intraprostatic inflammation, there is a hypothesis that TLR gene polymorphisms may be associated with prostate cancer risk. Although a number of comprehensive studies have been conducted on large samples in various countries, reliable connections between these single nucleotide polymorphisms and prostate cancer risk, stage, grade, aggressiveness, ability to metastasize, and mortality have not been detected. Results have also varied slightly in different populations. The data obtained regarding the absence of connection between the polymorphisms of the genes encoding interleukin-1 receptor-associated kinases (IRAK1 and IRAK4) and prostate cancer risk might indicate a lack of association between inherited variation in the TLR signaling pathway and prostate cancer risk. It is possible to consider that polymorphisms of genes encoding TLRs and proteins of the TLR pathway also do not play a major role in the etiology and pathogenesis of prostate cancer. Feasibly, it would be better to focus research on associations between TLR single nucleotide polymorphisms and cancer risk in other infection-related cancer types

  14. Characterization of host responses induced by Toll-like receptor ligands in chicken cecal tonsil cells.

    Taha-Abdelaziz, Khaled; Alkie, Tamiru Negash; Hodgins, Douglas C; Shojadoost, Bahram; Sharif, Shayan

    2016-06-01

    The innate responses of cecal tonsils against invading microorganisms are mediated by conserved pattern recognition receptors (PRRs) such as the Toll-like receptors (TLRs). TLRs expressed by mammalian and avian immune system cells have the capability to recognize pathogen-associated molecular patterns (PAMPs). Although, the role of TLR ligands in innate and adaptive responses in chickens has been characterized in spleen and bursa of Fabricius, considerably less is known about responses in cecal tonsils. The aim of the current study was to assess responses of mononuclear cells from cecal tonsils to treatment with the TLR2, TLR4 and TLR21 ligands, Pam3CSK4, lipopolysaccharide (LPS), and CpG oligodeoxynucleotide (ODN), respectively. All three ligands induced significant up-regulation of interferon (IFN)-γ, interleukin (IL)-1β, IL-6 and CxCLi2/IL-8, whereas no significant changes were observed in expression of IL-13 or the antimicrobial peptides, avian β-defensin (AvBD) 1, AvBD2 and cathelicidin 3 (CATHL-3). In general, CpG ODN elicited the highest cytokine responses by cecal tonsil mononuclear cells, inducing significantly higher expression compared to LPS and Pam3CSK4, for IFNγ, IL-1β, IL-6 and CxCLi2 at various time points. These findings suggest the potential use of TLR21 ligands as mucosal vaccine adjuvants, especially in the context of pathogens of the intestinal tract. PMID:27185259

  15. Toll-Like Receptor 9 Promotes Cardiac Inflammation and Heart Failure during Polymicrobial Sepsis

    Ralph Lohner

    2013-01-01

    Full Text Available Background. Aim was to elucidate the role of toll-like receptor 9 (TLR9 in cardiac inflammation and septic heart failure in a murine model of polymicrobial sepsis. Methods. Sepsis was induced via colon ascendens stent peritonitis (CASP in C57BL/6 wild-type (WT and TLR9-deficient (TLR9-D mice. Bacterial load in the peritoneal cavity and cardiac expression of inflammatory mediators were determined at 6, 12, 18, 24, and 36 h. Eighteen hours after CASP cardiac function was monitored in vivo. Sarcomere length of isolated cardiomyocytes was measured at 0.5 to 10 Hz after incubation with heat-inactivated bacteria. Results. CASP led to continuous release of bacteria into the peritoneal cavity, an increase of cytokines, and differential regulation of receptors of innate immunity in the heart. Eighteen hours after CASP WT mice developed septic heart failure characterised by reduction of end-systolic pressure, stroke volume, cardiac output, and parameters of contractility. This coincided with reduced cardiomyocyte sarcomere shortening. TLR9 deficiency resulted in significant reduction of cardiac inflammation and a sustained heart function. This was consistent with reduced mortality in TLR9-D compared to WT mice. Conclusions. In polymicrobial sepsis TLR9 signalling is pivotal to cardiac inflammation and septic heart failure.

  16. Expression profiles and function of Toll-like receptors in human corneal epithelia

    WU Xin-yi; GAO Jian-lu; REN Mei-yu

    2007-01-01

    Background Toll-like receptors play an important role in the human immune system. This study was conducted to investigate the expression profiles and function of Toll-like receptor (TLR)1-9 in human corneal epithelium.Methods The expression of TLR1-9 mRNA in 20 human donor corneal epithelia samples abraded during photorefractive keratotomy (PRK) and cultivated telomerase-immortalized human corneal epithelial cells (THCEs) was examined by semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis. Human peripheral blood mononuclear cells (PBMCs) were used as positive controls. The expression of the TLR2 and TLR4 proteins was detected by Western analysis. ELISA was used to detect IL-8 secretion from THCEs challenged with ligands for TLR3 and TLR4 with and without antibody blockade.Results The expression of TLR1-9 at the mRNA level was detected in the epithelia of 20 patients and in THCE.Significant differences among individuals were observed. One patient was found to lack of the expression of TLR3, 4, 6 and 8, whereas another did not express TLR5. The expression of TLR2 and TLR4 protein was detected in human corneal epithelial cells. As THCE cells express TLR1-9, cells were challenged with lipopolysaccharides (LPS) and poly I:C to determine whether TLR4 and TLR3 were functional. The results showed that secretion of IL-8 by cells stimulated with LPS and Poly I:C was 7 to 10 fold greater than secretion by unchallenged cells. Blocking TLR4 with an anti-TLR4 antibody significantly inhibited the LPS-induced IL-8 production by THCE (P<0.05).Conclusion Human corneal epithelial cells express multiple TLRs and are able to recognize LPS and poly I:C. Different expression profiles among individuals suggest that differences in the susceptibilities and sensitivities to bacterial and viral infection in human populations relate to different patterns of TLR expression.

  17. Chandipura Virus infection in mice: the role of toll like receptor 4 in pathogenesis

    Anukumar Balakrishnan

    2012-05-01

    Full Text Available Abstract Background The susceptibility of mice and humans to Chandipura virus infection is age-dependent. Upon experimental infection, mice secrete significant amounts of proinflammatory cytokines. Similarly, children who recover from natural infection with the virus show significant amounts of TNF-α production, suggesting that innate immunity plays a major role in the response to Chandipura virus. Toll-like receptors (TLR are key host molecules involved in innate immune responses in infections. Therefore, the aim of this study was to examine the role of TLR in the response to Chandipura virus infection. Methods The mouse monocyte-macrophage cell line, RAW 264.7, and C3H/HeJ mice were used as models. Micro array techniques were used to identify the type of TLR involved in the response to infection. The results were validated by examining TLR expression using flow cytometry and by measuring the levels of proinflammatory cytokines and nitric oxide (NO in the culture supernatants using bead assays and the Griess method, respectively. The pathogenic role of Toll-like receptor 4 (TLR4 was studied in a TLR4 mutant strain of mice -C3H/HeJ and the results compared with those from wild-type mice- C3H/CaJ. The pathogenic effects of NO were studied by treating experimentally infected mice with the NO inhibitor, aminoguanidine (AG. Results The micro array results showed that TLR4 was regulated after Chandipura virus infection. At high multiplicities of infection (10 MOI, RAW cells up- regulated cell surface expression of TLR4 and secreted significant amounts of TNF-α, MCP-1, IL-10 and IL-12 and NO. The survival rate of C3H/HeJ mice was higher than those of wild-type C3H/CaJ mice. The survived C3H/HeJ mice secreted significant quantity of MCP-1 and IFN-γ cytokines and cleared virus from brain. Similarly, the survival rate of AG-treated mice was higher than those of the untreated controls. Conclusions Chandipura virus regulates TLR4, which leads to the

  18. Neuroexcitatory effects of morphine-3-glucuronide are dependent on Toll-like receptor 4 signaling

    Due Michael R

    2012-08-01

    Full Text Available Abstract Background Multiple adverse events are associated with the use of morphine for the treatment of chronic non-cancer pain, including opioid-induced hyperalgesia (OIH. Mechanisms of OIH are independent of opioid tolerance and may involve the morphine metabolite morphine-3-glucuronide (M3G. M3G exhibits limited affinity for opioid receptors and no analgesic effect. Previous reports suggest that M3G can act via the Toll-like receptor 4 (TLR4/myeloid differentiation protein-2 (MD-2 heterodimer in the central nervous system to elicit pain. Methods Immunoblot and immunocytochemistry methods were used to characterize the protein expression of TLR4 present in lumbar dorsal root ganglion (DRG. Using in vitro intracellular calcium and current clamp techniques, we determined whether TLR4 activation as elicited by the prototypical agonists of TLR4, lipopolysaccharide (LPS and M3G, contributed to changes in intracellular calcium and increased excitation. Rodents were also injected with M3G to determine the degree to which M3G-induced tactile hyperalgesia could be diminished using either a small molecule inhibitor of the MD-2/TLR4 complex in rats or TLR4 knockout mice. Whole cell voltage-clamp recordings were made from small- and medium-diameter DRG neurons (25 μm  Results We observed that TLR4 immunoreactivity was present in peptidergic and non-peptidergic sensory neurons in the DRG. Non-neuronal cells in the DRG lacked evidence of TLR4 expression. Approximately 15% of assayed small- and medium-diameter sensory neurons exhibited a change in intracellular calcium following LPS administration. Both nociceptive and non-nociceptive neurons were observed to respond, and approximately 40% of these cells were capsaicin-insensitive. Increased excitability observed in sensory neurons following LPS or M3G could be eliminated using Compound 15, a small molecule inhibitor of the TLR4/MD-2 complex. Likewise, systemic injection of M3G induced rapid tactile, but

  19. Contrasting patterns of polymorphism and selection in bacterial-sensing toll-like receptor 4 in two house mouse subspecies : Contrasting patterns of polymorphism and selection in bacterial-sensing toll-like receptor 4 in two house mouse subspecies

    Fornuskova, Alena; Bryja, Josef; Vinkler, Michal; Macholan, Milos; Pialek, Jaroslav

    2014-01-01

    Detailed investigation of variation in genes involved in pathogen recognition is crucial for understanding co-evolutionary processes between parasites and their hosts. Triggering immediate innate response to invading microbes, Toll-like receptors (TLRs) belong presently among the best-studied receptors of vertebrate immunity. TLRs exhibit remarkable interspecific variation and also intra-specific polymorphism is well documented. In humans and laboratory mice, several studies have recently sho...

  20. EPA and DHA exposure alters the inflammatory response but not the surface expression of toll-like receptor 4 in macrophages

    Honda, Kaori L.; Lamon-Fava, Stefania; Matthan, Nirupa R.; Wu, Dayong; Lichtenstein, Alice H

    2014-01-01

    Dietary intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and their respective enrichment in cell membranes have been negatively associated with atherosclerotic lesion development. This effect may be mediated, in part, by dampened inflammatory response of macrophages triggered by toll-like receptor 4 (TLR4) activation. This study investigated the influence of membrane fatty acid profile on TLR4-mediated inflammation in RAW 264.7 macrophages. Cells pretreated with myristic a...

  1. Specific Oligopeptides in Fermented Soybean Extract Inhibit NF-κB-Dependent iNOS and Cytokine Induction by Toll-Like Receptor Ligands

    Lee, Woo Hyung; Wu, Hong Min; LEE, CHAN GYU; Sung, Dae Il; Song, Hye Jung; Matsui, Toshiro; Kim, Han Bok; Kim, Sang Geon

    2014-01-01

    The ethanol extract of fermented soybean from Glycine max (chungkookjang, CHU) has been claimed to have chemopreventive and cytoprotective effects. In the present study, we examined the inhibitory effect of CHU on inducible nitric oxide synthase (iNOS) and cytokine induction by toll-like receptor (TLR) ligands treatment and attempted to identify the responsible active components. Nitric oxide (NO) content and iNOS levels in the media or RAW264.7 cells were measured using the Griess reagent an...

  2. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor 1α

    Alessio Paone; Roberta Galli; Chiara Gabellini; Dmitriy Lukashev; Donatella Starace; Agnes Gorlach; Paola De Cesaris; Elio Ziparo; Donatella Del Bufalo; Sitkovsky, Michail V.; Antonio Filippini; Anna Riccioli

    2010-01-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible...

  3. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor 1α1

    Paone, Alessio; Galli, Roberta; Gabellini, Chiara; Lukashev, Dmitriy; Starace, Donatella; Gorlach, Agnes; Cesaris, Paola; Ziparo, Elio; Del Bufalo, Donatella; Sitkovsky, Michail V.; Filippini, Antonio; Riccioli, Anna

    2010-01-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible...

  4. Genomics in cardiovascular diseases: analysis of the importance of the toll-like receptor signaling pathway

    Bustamante J

    2012-10-01

    Full Text Available J Bustamante,1 E Tamayo,2 J Herreros3,41Department of Cardiovascular Surgery, Hospital Universitario La Princesa, Madrid, 2Department of Anesthesiology and Intensive Care, Hospital Clinico Universitario de Valladolid, Valladolid, 3Department of Cardiovascular Surgery, Hospital Universitario Valdecilla, Santander, 4Biomedical Engineering Institute of Santander, Santander, SpainAbstract: The development of techniques for genomics study makes it possible for us to further our knowledge about the physiopathology of various immunological or infectious diseases. These techniques improve our understanding of the development and evolution of such diseases, including those of cardiovascular origin, whilst they help to bring about the design of new therapeutic strategies. We are reviewing the genetic alterations of immunity in said field, and focusing on the signaling pathway of toll-like receptors because not only does this play a decisive role in response to microorganisms, it is also heavily involved in modulating the inflammatory response to tissue damage, a side effect of numerous cardiovascular diseases. These alterations in tissue homeostasis are present under a wide range of circumstances, such as reperfusion ischemia (myocardial infarction phenomena, arteriosclerosis, or valvulopathy.Keywords: genome-wide association study, single-nucleotide polymorphism, innate immune system, ischemic/reperfusion, myocardial infarction

  5. Network Analysis of Neurodegenerative Disease Highlights a Role of Toll-Like Receptor Signaling

    Thanh-Phuong Nguyen

    2014-01-01

    Full Text Available Despite significant advances in the study of the molecular mechanisms altered in the development and progression of neurodegenerative diseases (NDs, the etiology is still enigmatic and the distinctions between diseases are not always entirely clear. We present an efficient computational method based on protein-protein interaction network (PPI to model the functional network of NDs. The aim of this work is fourfold: (i reconstruction of a PPI network relating to the NDs, (ii construction of an association network between diseases based on proximity in the disease PPI network, (iii quantification of disease associations, and (iv inference of potential molecular mechanism involved in the diseases. The functional links of diseases not only showed overlap with the traditional classification in clinical settings, but also offered new insight into connections between diseases with limited clinical overlap. To gain an expanded view of the molecular mechanisms involved in NDs, both direct and indirect connector proteins were investigated. The method uncovered molecular relationships that are in common apparently distinct diseases and provided important insight into the molecular networks implicated in disease pathogenesis. In particular, the current analysis highlighted the Toll-like receptor signaling pathway as a potential candidate pathway to be targeted by therapy in neurodegeneration.

  6. Expression of Toll-Like Receptors on Breast Tumors: Taking a Toll on Tumor Microenvironment

    Breast cancer remains a major cause of death in women in the developed world. As Toll-like receptors (TLRs) are widely expressed on tumor cells and play important roles in the initiation and progression of cancer, they may thus serve as important targets and have an effective perspective on breast cancer treatment. Expression of TLRs on breast cancer cells and mononuclear inflammatory cells can promote inflammation and cell survival in the tumor microenvironment. Inflammation and cancer are related. It is well known that persistent inflammatory conditions can induce cancer formation, due to production of cytokines and chemokines, which play a crucial role in promoting angiogenesis, metastasis, and subversion of adaptive immunity. TLR signaling in tumor cells can mediate tumor cell immune escape and tumor progression, and it is regarded as one of the mechanisms for chronic inflammation in tumorigenesis and progression. This paper delineates the expression of various TLRs in promotion of inflammation and development of mammary tumors. Understanding the mechanisms through which TLRs on breast cancer cells and inflammatory cells regulate growth, survival, and metastatic progression can make them potential targets for breast cancer therapy

  7. Toll-like receptor signalling in regenerative myogenesis: friend and foe.

    Hindi, Sajedah M; Kumar, Ashok

    2016-06-01

    Skeletal muscle regeneration in normal and diseased muscle is regulated by multiple factors and cells present in the injured muscle micro-environment. In addition to muscle progenitor cells, several immunocytes participate in the regenerative response. Among them, macrophages are one of the most important components of the immune response that governs the step-wise progression of muscle regeneration. The initial role of macrophages is to phagocytose muscle cell debris and later, through their transition to an anti-inflammatory phenotype, they promote regeneration. However, in several genetic muscle disorders, continuous muscle injury disrupts the balance between pro-inflammatory and anti-inflammatory macrophages, leading to an overall inflammatory milieu and inhibition of muscle regeneration. Accumulating evidence suggests that Toll-like receptor (TLR)-mediated signalling plays an important role in the regulation of macrophage phenotypes during regenerative myogenesis in response to both acute and chronic muscle injury. Here, we discuss the role of TLR signalling in regulating macrophage phenotypes and skeletal muscle regeneration in healthy and diseased muscle. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:26956975

  8. Expression of Toll-like receptors in nasal epithelium in allergic rhinitis.

    Renkonen, Jutta; Toppila-Salmi, Sanna; Joenväärä, Sakari; Mattila, Pirkko; Parviainen, Ville; Hagström, Jaana; Haglund, Caj; Lehtonen, Mikko; Renkonen, Risto

    2015-08-01

    Toll-like receptors (TLRs) are important in barrier homeostasis, but their role in airborne allergies is not fully understood. The aim was to evaluate baseline and allergen-induced expression of TLR proteins in nasal epithelium during allergic rhinitis. Nineteen otherwise healthy non-smoking volunteers both allergic to birch pollen and non-allergic controls were enrolled. We took nasal biopsies before and after off-seasonal intranasal birch pollen or diluent challenge. The expression of epithelial TLR1-7, TLR9-10, and MyD88 proteins was immunohistochemically evaluated from the nasal biopsies. The TLR1-3 and TLR5-10 mRNAs were observed by RNA-microarray. Baseline epithelial expression of TLR proteins was wide and identical in controls and atopics. After off-seasonal intranasal birch pollen challenge, a negative change in the expression score of TLR1 and TLR6 proteins was detected in the atopic group. TLR mRNA expression was not affected by birch pollen challenge. Nasal epithelium seems to express all known TLRs. The mechanisms by which TLR1, and TLR6 proteins could affect pollen allergen transport need further studies. PMID:26061394

  9. Molecular Regulation of Toll-like Receptors in Asthma and COPD

    Zuo, Li; Lucas, Kurt; Fortuna, Christopher A.; Chuang, Chia-Chen; Best, Thomas M.

    2015-01-01

    Asthma and chronic obstructive pulmonary disease (COPD) have both been historically associated with significant morbidity and financial burden. These diseases can be induced by several exogenous factors, such as pathogen-associated molecular patterns (PAMPs) (e.g., allergens and microbes). Endogenous factors, including reactive oxygen species, and damage-associated molecular patterns (DAMPs) recognized by toll-like receptors (TLRs), can also result in airway inflammation. Asthma is characterized by the dominant presence of eosinophils, mast cells, and clusters of differentiation (CD)4+ T cells in the airways, while COPD typically results in the excessive formation of neutrophils, macrophages, and CD8+ T cells in the airways. In both asthma and COPD, in the respiratory tract, TLRs are the primary proteins of interest associated with the innate and adaptive immune responses; hence, multiple treatment options targeting TLRs are being explored in an effort to reduce the severity of the symptoms of these disorders. TLR-mediated pathways for both COPD and asthma have their similarities and differences with regards to cell types and the pro-inflammatory cytotoxins present in the airway. Because of the complex TLR cascade, a variety of treatments have been used to minimize airway hypersensitivity and promote bronchodilation. Although unsuccessful at completely alleviating COPD and severe asthmatic symptoms, new studies are focused on possible targets within the TLR cascade to ameliorate airway inflammation. PMID:26617525

  10. Placental Trophoblast Responses to Porphyromonas gingivalis Mediated by Toll-like Receptor-2 and -4

    Banun Kusumawardani

    2013-09-01

    Full Text Available Trophoblast participates in preventing allorecognition and controlling pathogens that compromise fetal wellbeing. Toll-like receptors recognize conserved sequences on the pathogens surface and trigger effector cell functions. Porphyromonas gingivalis is thought to spread to the umbilical cord and cause fetal growth restriction. Objective: To characterize expression and function of TLR-2 and TLR-4 in trophoblast cells from Porphyromonas gingivalisinfected pregnant rats. Methods: Live Porphyromonas gingivalis were challenged into the maxillary first molar subgingival sulcus of female rats before and/or during pregnancy and sacrified on gestational day (GD 14 and 20. Porphyromonas gingivalis was detected by API-ZYM system in the maternal blood of the retro-orbital venous plexus and the umbilical cord. TLR-2 and TLR-4 expressions in trophoblast cells was detected by immunohistochemistry. Results: Porphyromonas gingivalis was first detected in the maternal blood and finally spread to the umbilical cord. Syncytiotrophoblast, spongitrophoblast and trophoblastic giant cell in treated groups had significantly higher expression of TLR-2 and TLR-4 than control group (p<0.05. Conclusion: Syncytiotrophoblast, spongitrophoblast and trophoblastic giant cell are able to recognize Porphyromonas gingivalis through TLR-2 and TLR-4 expression. The ligation of TLR-2 and TLR-4 promoted cytokine production and induced trophoblast cell death. These findings strengthen links between periodontal disease and fetal growth restriction.DOI: 10.14693/jdi.v20i2.150

  11. Toll-like receptor-2 agonist functionalized biopolymer for mucosal vaccination.

    Heuking, S; Iannitelli, A; Di Stefano, A; Borchard, G

    2009-11-01

    The objective of this study was to provide a new water-soluble chitosan derivative being functionalized with a Toll-like receptor-2 (TLR-2) agonist. At first, we synthesized the water-soluble TLR-2 agonist omega-amido-[N(alpha)-palmitoyl-oxy-S-[2,3-bis(palmitoyl-oxy)-(2R)-propyl]-[R]-cysteinyl]-alpha-amino poly(ethylene glycol) (Pam(3)Cys-PEG-NH(2)), which was characterized by (1)H and (13)C NMR as well as mass spectroscopy. Secondly, Pam(3)Cys-PEG-NH(2) was then successfully grafted to 6-O-carboxymethyl-N,N,N-trimethyl chitosan polymers (CM-TMC) using EDC/NHS as condensing agents. The copolymer was analysed by means of (1)H and (13)C NMR and FTIR spectroscopy. (13)C NMR spectroscopy did not deliver evidence that an amide bond was formed between CM-TMC and Pam(3)Cys-PEG-NH(2). However, (1)H NMR and FTIR spectroscopy demonstrated clearly that successful grafting took place. Based upon these results, this new TLR-2 functionalized biopolymer merits further investigations as material for vaccine delivery systems. PMID:19782879

  12. Intra-uterine Growth Restriction Downregulates the Hepatic Toll Like Receptor-4 Expression and Function

    Ozlem Equils

    2005-01-01

    Full Text Available Maternal starvation is a significant cause of intrauterine growth restriction (IUGR in the world and increases the risk of infection in the neonate. We examined the effect of maternal starvation on Toll like receptor (TLR4 expression in hepatic, splenic and intestinal tissues obtained from the adult IUGR offspring of prenatal calorie restricted rats. The hepatic TLR4 protein concentration was undetectable in the IUGR rats that had restricted milk intake during the suckling period (SM/SP; n = 4, p < 0.05 as compared to the normal growth controls (CM/CP; n=4, and access to ad lib milk intake during the sucking period partially corrected the hepatic TLR4 expression (SM/CP; n = 4. IUGR had no effect on the splenic (n = 4 or intestinal (n = 4 TLR4 mRNA levels. In the liver, IUGR led to a 20% increase in baseline tumor necrosis factor (TNF-α mRNA expression ( p < 0.03 and a 70% increase in interleukin-1β (IL-1β mRNA expression ( p < 0.008 as compared to the control rats (CM/CP; n = 7. LPS-induced hepatic TNF-α release was significantly higher in SM/SP as compared to CM/CP. We propose that IUGR dysregulates TLR4 expression and function in the offspring, which may help explain the increased risk of Gram-negative sepsis and inflammatory diseases in this population.

  13. Characterization of promoter sequence of toll-like receptor genes in Vechur cattle

    R. Lakshmi

    2016-06-01

    Full Text Available Aim: To analyze the promoter sequence of toll-like receptor (TLR genes in Vechur cattle, an indigenous breed of Kerala with the sequence of Bos taurus and access the differences that could be attributed to innate immune responses against bovine mastitis. Materials and Methods: Blood samples were collected from Jugular vein of Vechur cattle, maintained at Vechur cattle conservation center of Kerala Veterinary and Animal Sciences University, using an acid-citrate-dextrose anticoagulant. The genomic DNA was extracted, and polymerase chain reaction was carried out to amplify the promoter region of TLRs. The amplified product of TLR2, 4, and 9 promoter regions was sequenced by Sanger enzymatic DNA sequencing technique. Results: The sequence of promoter region of TLR2 of Vechur cattle with the B. taurus sequence present in GenBank showed 98% similarity and revealed variants for four sequence motifs. The sequence of the promoter region of TLR4 of Vechur cattle revealed 99% similarity with that of B. taurus sequence but not reveals significant variant in motifregions. However, two heterozygous loci were observed from the chromatogram. Promoter sequence of TLR9 gene also showed 99% similarity to B. taurus sequence and revealed variants for four sequence motifs. Conclusion: The results of this study indicate that significant variation in the promoter of TLR2 and 9 genes in Vechur cattle breed and may potentially link the influence the innate immunity response against mastitis diseases.

  14. Novel Toll-like receptor-4 deficiency attenuates trastuzumab (Herceptin induced cardiac injury in mice

    Yousif Nasser

    2011-10-01

    Full Text Available Abstract Background Cardiac inflammation and generation of oxidative stress are known to contribute to trastuzumab (herceptin induced cardiac toxicity. Toll-like receptors (TLRs are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signaling, we investigated whether or not TLR4 is involved in trastuzumab induced cardiotoxicity. Methods Seven days after a single injection of herceptin (2 mg/kg; i.p., left ventricular pressure volume loops were measured in HeN compotent (TLR4+/+ and HeJ mutant (TLR4-/- treated with trastuzumab and control mice. Immunofluorescent staining for monocyte infiltration and analyses of plasma by (ELISAs for different chemokines including: MCP-1and tumor necrosis factor-α (TNF-α, Western immunoblotting assay for ICAM-1, and used troponin I for cardiac injury marker. Results Trastuzumab injection resulted in an impairment of left ventricular function in TLR-4 competent (HeN, in contrast TLR4-/- trastuzumab mice showed improved left ventricular function EF%, CO; p -/-; p -/-, marked reduction of myocardial troponin-I levels in TLR4-deficient mice. Data are presented as means ± SE; n = 8 in each group p Conclusions Treatment with trastuzumab induces an inflammatory response that contributes to myocardial tissue TLR4 mediates chemokine expression (TNF-α, MCP-1and ICAM-1, so in experimental animals TLR4 deficiency improves left ventricular function and attenuates pathophysiological key mechanisms in trastuzumab induced cardiomyopathy.

  15. Association of Toll-like receptors 2, 3, and 4 genes polymorphisms with periapical pathosis risk

    Özan, Ülkü; Ocak, Zeynep; Özan, Fatih; Oktay, Elif-Aybala; Şahman, Halil; Yikilgan, İhsan; Oruçoğlu, Hasan; Er, Kürşat

    2016-01-01

    Background The aim of this study was to investigate the role of gene variations of Toll-like receptors (TLR) 2, 3, and 4 on genetic susceptibility to periapical pathosis. Material and Methods One hundred patients were included in the study and divided into two groups as follows; Control Group (n=50) that have root canal treatment and no periapical lesion, Patient Group (n=50) that have root canal treatment and periapical lesion. TLR2 Arg753Gln, TLR3 (c.1377C/T) and TLR4 Asp299Gly and Thr399Ile polymorphisms were genotyped by using PCR-RFLP. Genotypical analysis of control and patient groups were investigated to disclose whether there is any association between periapical lesions and gene variations. Results There are no significant statistical differences between control and patient groups according to TLR 2 and 4 gene sequence. On the contrary, CC allele detected 74% for TLR 3 in patient group, and this difference was found to be statistically significant (p endodontics. PMID:27031066

  16. Toll like receptor 2 and 4 polymorphisms in malaria endemic populations of India.

    Bali, Prerna; Pradhan, Sabyasachi; Sharma, Divya; Adak, Tridibes

    2013-02-01

    Toll like receptors (TLRs) play a pivotal role in recognizing the invading malaria parasite Plasmodium, thus genetic makeup of the exposed population can be of utmost importance for its predisposition to malaria. In this study 264 malaria patients from seven different eco epidemiological regions of India were genotyped for TLR2 and TLR4 polymorphisms using DNA sequencing methods. No variation was observed at residue positions 677 and 753 in TLR2 whereas residue positions 299 and 399 in TLR4 were highly polymorphic. The GC haplotype (Asp299Gly/Thr399Thr) was observed at the highest frequency in populations of East Singhbhum, Vizianagaram and North Goa and absent in Kolkata, Dakshin Kannada and Nicobar district. All polymorphisms were in Hardy Weinberg equilibrium. Populations of Kolkata, Nicobar district, Sundergarh and Dakshin Kannada were observed to be closely related. TLR2 polymorphism was absent in the Indian population and an overall heterogeneous pattern of TLR4 polymorphism can be attributed to genetic drift. However it can be inferred that GC haplotype is under the process of natural selection in the Indian population and one of the factors contributing to its selection could be predominance of Plasmodium falciparum in these regions. PMID:23200752

  17. Role of Toll-Like Receptors 2 and 4 in Pulmonary Inflammation and Injury Induced by Pneumolysin in Mice

    Dessing, M C; Hirst, R. A.; De Vos; Poll, van der, T.

    2009-01-01

    Background: Pneumolysin (PLN) is an intracellular toxin of Streptococcus pneumoniae that has been implicated as a major virulence factor in infections caused by this pathogen. Conserved bacterial motifs are recognized by the immune system by pattern recognition receptors among which the family of Toll-like receptors (TLRs) prominently features. The primary objective of the present study was to determine the role of TLR2 and TLR4 in lung inflammation induced by intrapulmonary delivery of PLN. ...

  18. Association of Single Nucleotide Polymorphisms in Toll-like Receptors with Acinetobacter baumanii Infectionin a Chinese Population

    He, Lei; Maohu LIN; Fan, Wensheng; Liu, Yunxi; SUO, Jijiang; Xing, Yubin; Jia, Ning

    2016-01-01

    Background: During recent years, infection of Acinetobacter baumanii showed a rapid growth in hospitals and community. Toll-like receptors (TLRs) are the most important pattern recognition receptors, which play a critical role during recognizing invading pathogens by the natural immune system. Our objective was to determine the associations of TLRs polymorphisms with the susceptibility to A. baumanii infection in a Chinese population. Methods: We carried out a case-control study, genotyping 1...

  19. Crystal structure of Toll-like receptor adaptor MAL/TIRAP reveals the molecular basis for signal transduction and disease protection

    Valkov, Eugene; Stamp, Anna; DiMaio, Frank; Baker, David; Verstak, Brett; Roversi, Pietro; Kellie, Stuart; Sweet, Matthew J.; Mansell, Ashley; Gay, Nicholas J.; Jennifer L Martin; Kobe, Bostjan

    2011-01-01

    Initiation of the innate immune response requires agonist recognition by pathogen-recognition receptors such as the Toll-like receptors (TLRs). Toll/interleukin-1 receptor (TIR) domain-containing adaptors are critical in orchestrating the signal transduction pathways after TLR and interleukin-1 receptor activation. Myeloid differentiation primary response gene 88 (MyD88) adaptor-like (MAL)/TIR domain-containing adaptor protein (TIRAP) is involved in bridging MyD88 to TLR2 and TLR4 in response...

  20. The role of toll-like receptor 4 in airway inflammation induced by diesel exhaust particles

    Inoue, Ken-ichiro; Yanagisawa, Rie; Hirano, Seishiro [National Institute for Environmental Studies, Environmental Health Sciences Division, Tsukuba (Japan); Takano, Hirohisa; Yoshikawa, Toshikazu [Kyoto Prefectural University of Medicine, Inflammation and Immunology, Graduate School of Medical Science, Kyoto (Japan); Ichinose, Takamichi [Oita University of Nursing and Health Science, Department of Health Science, Oita (Japan); Shimada, Akinori [Tottori University, Department of Veterinary Pathology, Faculty of Agriculture, Tottori (Japan)

    2006-05-15

    Although several studies have demonstrated that airway exposure to diesel exhaust particles (DEP) induces lung inflammation, the signaling pathways involved in the pathogenesis remain unclear. Toll-like receptors (TLRs) are generally accepted to be pathogen recognition receptors in mammalians. In the present study, we investigated the role of TLR-4 in DEP-induced lung inflammation and cytokine expression in the lung in TLR-4 point mutant (C3H/HeJ) mice and corresponding control (C3H/HeN) mice. Both the types of mice were randomized into four experimental groups that received vehicle or DEP (12 mg/kg body weight) by intratracheal instillation (n=8-10 in each group). Cellular profile of bronchoalveolar lavage (BAL) fluid, expressions of cytokines and chemokines in the lung, and circulatory fibrinogen levels were evaluated 24 h after the instillation.DEP challenge revealed a significant increase in the numbers of total cells and neutrophils in the BAL fluid as compared to vehicle challenge, however, the numbers were less in C3H/HeJ mice than in C3H/HeN mice. DEP exposure significantly induced the lung expression of interleukin (IL)-1{beta}, keratinocyte chemoattractant (KC), and macrophage inflammatory protein (MIP)-1{alpha} when compared to vehicle challenge in both genotypes of mice. In the presence of DEP, the level of MIP-1{alpha} was significantly lower in C3H/HeJ mice than in C3H/HeN mice, however, the levels of IL-1{beta}, KC, and fibrinogen showed opposite findings. These results suggest that TLR-4 is one of recognition receptors against DEP in the airways. (orig.)

  1. [The role of Toll-like receptors in the pathogenesis of allergic diseases - where is the truth?].

    Dębińska, Anna; Boznański, Andrzej

    2014-01-01

    Toll-like receptors (TLRs) are pattern recognition receptors crucial for the innate and adaptive immune response to pathogen-associated molecular patterns (PAMPs). TLR stimulation via microbial products activates antigen-presenting cells, influences the function of T regulatory cells (Treg), determines the Th1/Th2 balance and Th17 cell differentiation, and controls cytokine production in mast cells and activation of eosinophils. The role of TLR receptors in pathogenesis of allergic diseases results from the biological function that they play in activation and regulation of the immune response. However, the exact role still remains a controversial area. Whereas numerous epidemiological studies mainly indicate a protective effect of microbial exposure, experiments show that innate immune stimulation via TLRs may be involved in both development of and protection against allergic diseases. Timing, dose, site and intensity of exposure to environmental factors and host genetic predisposition are clearly crucial to understanding the interaction between innate immune stimulation and allergy development.Furthermore, extensive clinical trials suggest that ligands for TLRs provide new therapeutic targets for protection against and treatment of asthma and allergic rhinitis. The aim of this review is to summarize the current knowledge about the role of TLRs in pathogenesis of allergic diseases. We will further discuss how we can reconcile inconsistencies in the results of existing studies and review information on the potential use of ligands for TLRs in allergy prevention and therapy. PMID:24662791

  2. The role of Toll-like receptors in the pathogenesis of allergic diseases – where is the truth?

    Anna Dębińska

    2014-03-01

    Full Text Available Toll-like receptors (TLRs are pattern recognition receptors crucial for the innate and adaptive immune response to pathogen-associated molecular patterns (PAMPs. TLR stimulation via microbial products activates antigen-presenting cells, influences the function of T regulatory cells (Treg, determines the Th1/Th2 balance and Th17 cell differentiation, and controls cytokine production in mast cells and activation of eosinophils. The role of TLR receptors in pathogenesis of allergic diseases results from the biological function that they play in activation and regulation of the immune response. However, the exact role still remains a controversial area. Whereas numerous epidemiological studies mainly indicate a protective effect of microbial exposure, experiments show that innate immune stimulation via TLRs may be involved in both development of and protection against allergic diseases. Timing, dose, site and intensity of exposure to environmental factors and host genetic predisposition are clearly crucial to understanding the interaction between innate immune stimulation and allergy development.Furthermore, extensive clinical trials suggest that ligands for TLRs provide new therapeutic targets for protection against and treatment of asthma and allergic rhinitis. The aim of this review is to summarize the current knowledge about the role of TLRs in pathogenesis of allergic diseases. We will further discuss how we can reconcile inconsistencies in the results of existing studies and review information on the potential use of ligands for TLRs in allergy prevention and therapy.

  3. Characterization of Toll-like receptor gene expression in goldfish (Carassius auratus) during Dactylogyrus intermedius infection.

    Tu, Xiao; Liu, Lei; Qi, Xiaozhou; Chen, Weichao; Wang, Gaoxue; Ling, Fei

    2016-10-01

    Toll-like receptors (TLRs), the first and best understood innate immune receptors, play a notable role in the innate immune system by sensing pathogenic agents and initiating appropriate immune responses. However, studies about the roles of fish TLRs in response to the infection of the ectoparasitic monogenean Dactylogyrus intermedius have been surprisingly vacant. In the present study, cDNA fragments of five members of TLRs family in goldfish (Carassius auratus) were cloned and the expression patterns of nine TLRs in five tissues at different time points during D. intermedius infection were subsequently investigated. We found that the expressions of TLR4, TLR5, TLR20 and TLR22 were significantly elevated after infection at some time points, of which the transcription of TLR5 was progressively increased nearly in all tissues, whereas the mRNA levels of other TLRs (TLR2, 3, 7, 9 and 21) were down-regulated or showed no significant change compared with the control at most time points. Additionally, this paper was also conducted to explore the expression of above TLRs after re-infected with D. intermedius. The results showed a significant upregulation of TLR4, TLR5 and TLR22 in all tested tissues at these two time points, especially the levels of TLR4 and TLR22 expression, were even higher comparing with the first infection. Besides, tissue-specific expression analysis revealed that spleen featured the highest expressions of almost all the TLR-encoding genes among detected tissues. The informations obtained here could be helpful towards understanding the functions of TLRs in response to parasitic infection in goldfish and provide new insights for the development of preventive and therapeutic approaches against D. intermedius infection. PMID:27238769

  4. Toll-like receptor and antimicrobial peptide expression in the bovine endometrium

    Conlan R Steven

    2008-11-01

    Full Text Available Abstract Background The endometrium is commonly infected with bacteria leading to severe disease of the uterus in cattle and humans. The endometrial epithelium is the first line of defence for this mucosal surface against bacteria and Toll-like receptors (TLRs are a critical component of the innate immune system for detection of pathogen associated molecular patterns (PAMPs. Antimicrobial peptides, acute phase proteins and Mucin-1 (MUC-1 also provide non-specific defences against microbes on mucosal surfaces. The present study examined the expression of innate immune defences in the bovine endometrium and tested the hypothesis that endometrial epithelial cells express functional receptors of the TLR family and the non-specific effector molecules for defence against bacteria. Methods Bovine endometrial tissue and purified populations of primary epithelial and stromal cells were examined using RT-PCR for gene expression of TLRs, antimicrobial peptides and MUC-1. Functional responses were tested by evaluating the secretion of prostaglandin E2 and acute phase proteins when cells were treated with bacterial PAMPs such as bacterial lipopolysaccharide (LPS and lipoproteins. Results The endometrium expressed TLRs 1 to 10, whilst purified populations of epithelial cells expressed TLRs 1 to 7 and 9, and stromal cells expressed TLRs 1 to 4, 6, 7, 9 and 10. The TLRs appear to be functional as epithelial cells secreted prostaglandin E2 in response to bacterial PAMPs. In addition, the epithelial cells expressed antimicrobial peptides, such as Tracheal and Lingual Antimicrobial Peptides (TAP and LAP and MUC-1, which were upregulated when the cells were treated with LPS. However, the epithelial cells did not express appreciable amounts of the acute phase proteins haptoglobin or serum amyloid A. Conclusion Epithelial cells have an essential role in the orchestration of innate immune defence of the bovine endometrium and are likely to be the key to prevention of

  5. Tenascin C upregulates interleukin-6 expression in human cardiac myofibroblasts via toll-like receptor 4

    Maqbool, Azhar; Spary, Emma J; Manfield, Iain W; Ruhmann, Michaela; Zuliani-Alvarez, Lorena; Gamboa-Esteves, Filomena O; Porter, Karen E; Drinkhill, Mark J; Midwood, Kim S; Turner, Neil A

    2016-01-01

    AIM: To investigate the effect of Tenascin C (TNC) on the expression of pro-inflammatory cytokines and matrix metalloproteinases in human cardiac myofibroblasts (CMF). METHODS: CMF were isolated and cultured from patients undergoing coronary artery bypass grafting. Cultured cells were treated with either TNC (0.1 μmol/L, 24 h) or a recombinant protein corresponding to different domains of the TNC protein; fibrinogen-like globe (FBG) and fibronectin type III-like repeats (TNIII 5-7) (both 1 μmol/L, 24 h). The expression of the pro-inflammatory cytokines; interleukin (IL)-6, IL-1β, TNFα and the matrix metalloproteinases; MMPs (MMP1, 2, 3, 9, 10, MT1-MMP) was assessed using real time RT-PCR and western blot analysis. RESULTS: TNC increased both IL-6 and MMP3 (P < 0.01) mRNA levels in cultured human CMF but had no significant effect on the other markers studied. The increase in IL-6 mRNA expression was mirrored by an increase in protein secretion as assessed by enzyme-linked immunosorbant assay (P < 0.01). Treating CMF with the recombinant protein FBG increased IL-6 mRNA and protein (P < 0.01) whereas the recombinant protein TNIII 5-7 had no effect. Neither FBG nor TNIII 5-7 had any significant effect on MMP3 expression. The expression of toll-like receptor 4 (TLR4) in human CMF was confirmed by real time RT-PCR, western blot and immunohistochemistry. Pre-incubation of cells with TLR4 neutralising antisera attenuated the effect of both TNC and FBG on IL-6 mRNA and protein expression. CONCLUSION: TNC up-regulates IL-6 expression in human CMF, an effect mediated through the FBG domain of TNC and via the TLR4 receptor. PMID:27231521

  6. Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia

    Toll like receptor 4 (TLR4) has been characterized for its ability to recognize bacterial endotoxin lipopolysaccharide (LPS). Considering that infections or inflammatory processes might contribute to the progression of pituitary tumors, we analyzed the TLR4 functional role by evaluating the LPS effect on lactotroph proliferation in primary cultures from experimental pituitary tumors, and examined the involvement of PI3K-Akt and NF-κB activation in this effect. In addition, the role of 17β-estradiol as a possible modulator of LPS-induced PRL cell proliferation was further investigated. In estrogen-induced hyperplasic pituitaries, LPS triggered lactotroph cell proliferation. However, endotoxin failed to increase the number of lactotrophs taking up BrdU in normal pituitaries. Moreover, incubation with anti-TLR4 antibody significantly reduced LPS-induced lactotroph proliferation, suggesting a functional role of this receptor. As a sign of TLR4 activation, an LPS challenge increased IL-6 release in normal and tumoral cells. By flow cytometry, TLR4 baseline expression was revealed at the plasma membrane of tumoral lactotrophs, without changes noted in the percentage of double PRL/TLR4 positive cells after LPS stimulus. Increases in TLR4 intracellular expression were detected as well as rises in CD14, p-Akt and NF-κB after an LPS challenge, as assessed by western blotting. The TLR4/PRL and PRL/NF-κB co-localization was also corroborated by immunofluorescence and the involvement of PI3K/Akt signaling in lactotroph proliferation and IL-6 release was revealed through the PI3K inhibitor Ly-294002. In addition, 17β-estradiol attenuated the LPS-evoked increase in tumoral lactotroph proliferation and IL-6 release. Collectively these results demonstrate the presence of functional TLR4 in lactotrophs from estrogen-induced hyperplasic pituitaries, which responded to the proliferative stimulation and IL-6 release induced by LPS through TLR4/CD14, with a contribution of the PI3K

  7. Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia

    Sabatino, María Eugenia; Sosa, Liliana del Valle; Petiti, Juan Pablo; Mukdsi, Jorge Humberto [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina); Mascanfroni, Iván Darío; Pellizas, Claudia Gabriela [Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Av. Haya de la Torre y Medina Allende, Ciudad Universitaria, CP 5000, Córdoba (Argentina); Gutiérrez, Silvina; Torres, Alicia Inés [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina); De Paul, Ana Lucía, E-mail: adepaul@cmefcm.uncor.edu [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina)

    2013-11-15

    Toll like receptor 4 (TLR4) has been characterized for its ability to recognize bacterial endotoxin lipopolysaccharide (LPS). Considering that infections or inflammatory processes might contribute to the progression of pituitary tumors, we analyzed the TLR4 functional role by evaluating the LPS effect on lactotroph proliferation in primary cultures from experimental pituitary tumors, and examined the involvement of PI3K-Akt and NF-κB activation in this effect. In addition, the role of 17β-estradiol as a possible modulator of LPS-induced PRL cell proliferation was further investigated. In estrogen-induced hyperplasic pituitaries, LPS triggered lactotroph cell proliferation. However, endotoxin failed to increase the number of lactotrophs taking up BrdU in normal pituitaries. Moreover, incubation with anti-TLR4 antibody significantly reduced LPS-induced lactotroph proliferation, suggesting a functional role of this receptor. As a sign of TLR4 activation, an LPS challenge increased IL-6 release in normal and tumoral cells. By flow cytometry, TLR4 baseline expression was revealed at the plasma membrane of tumoral lactotrophs, without changes noted in the percentage of double PRL/TLR4 positive cells after LPS stimulus. Increases in TLR4 intracellular expression were detected as well as rises in CD14, p-Akt and NF-κB after an LPS challenge, as assessed by western blotting. The TLR4/PRL and PRL/NF-κB co-localization was also corroborated by immunofluorescence and the involvement of PI3K/Akt signaling in lactotroph proliferation and IL-6 release was revealed through the PI3K inhibitor Ly-294002. In addition, 17β-estradiol attenuated the LPS-evoked increase in tumoral lactotroph proliferation and IL-6 release. Collectively these results demonstrate the presence of functional TLR4 in lactotrophs from estrogen-induced hyperplasic pituitaries, which responded to the proliferative stimulation and IL-6 release induced by LPS through TLR4/CD14, with a contribution of the PI3K

  8. Induction of IgG3 to LPS via Toll-like receptor 4 co-stimulation.

    Francisco J Quintana

    Full Text Available B-cells integrate antigen-specific signals transduced via the B-cell receptor (BCR and antigen non-specific co-stimulatory signals provided by cytokines and CD40 ligation in order to produce IgG antibodies. Toll-like receptors (TLRs also provide co-stimulation, but the requirement for TLRs to generate T-cell independent and T-cell dependent antigen specific antibody responses is debated. Little is known about the role of B-cell expressed TLRs in inducing antigen-specific antibodies to antigens that also activate TLR signaling. We found that mice lacking functional TLR4 or its adaptor molecule MyD88 harbored significantly less IgG3 natural antibodies to LPS, and required higher amounts of LPS to induce anti-LPS IgG3. In vitro, BCR and TLR4 signaling synergized, lowering the threshold for production of T-cell independent IgG3 and IL-10. Moreover, BCR and TLR4 directly associate through the transmembrane domain of TLR4. Thus, in vivo, BCR/TLR synergism could facilitate the induction of IgG3 antibodies against microbial antigens that engage both innate and adaptive B-cell receptors. Vaccines might exploit BCR/TLR synergism to rapidly induce antigen-specific antibodies before significant T-cell responses arise.

  9. Immune response associated with Toll-like receptor 4 signaling pathway leads to steroid-induced femoral head osteonecrosis

    Tian, Lei; Wen, Qi; Dang, Xiaoqian; You, Wulin; Fan, Lihong; Wang, Kunzheng

    2014-01-01

    Background Femoral head osteonecrosis is frequently observed in patients treated with excessive corticosteroids. The objective of the current study was to establish a rat model to investigate the disruption of immune response in steroid-induced femoral head osteonecrosis via Toll-like receptor 4 (TLR4) signaling pathway. Methods Male SD rats were divided into the treatment group (group A) and the model group (group B) consisting of 24 rats each, and were injected intramuscularly with 20 mg/kg...

  10. Vanadate from Air Pollutant Inhibits Hrs-Dependent Endosome Fusion and Augments Responsiveness to Toll-Like Receptors

    Mojca Zelnikar; Mojca Benčina; Roman Jerala; Mateja Manček-Keber

    2014-01-01

    There is a well-established association between exposure to air pollutants and pulmonary injuries. For example, metals found in ROFA (residual oil fly ash) increase susceptibility of mice as well as humans to microbial infections. In our research, we have found that vanadate substantially increased the response of several Toll-like receptors (TLRs) to stimulation with their ligands. Although vanadate caused generation of reactive oxygen species (ROS), the addition of ROS scavenger N-acetyl cy...

  11. Human decidual macrophages and NK cells differentially express Toll-like receptors and display distinct cytokine profiles upon TLR stimulation.

    ElisabethMenu; MarionDuriez; HéloïseQuillay; YoannMadec; RomainMarlin; Clairede Truchis; MonaRahmati

    2014-01-01

    Maternofetal pathogen transmission is partially controlled at the level of the maternal uterine mucosa at the fetal implantation site (the decidua basalis), where maternal and fetal cells are in close contact. Toll-like receptors (TLRs) may play an important role in initiating rapid immune responses against pathogens in the decidua basalis, however the tolerant microenvironment should be preserved in order to allow fetal development. Here we investigated the expression and functionality of TL...

  12. Human decidual macrophages and NK cells differentially express Toll-like receptors and display distinct cytokine profiles upon TLR stimulation

    Duriez, Marion; Quillay, Héloïse; Madec, Yoann; El Costa, Hicham; Cannou, Claude; Marlin, Romain; De Truchis, Claire; Rahmati, Mona; Barré-Sinoussi, Françoise; Nugeyre, Marie-Thérèse; Menu, Elisabeth

    2014-01-01

    Maternofetal pathogen transmission is partially controlled at the level of the maternal uterine mucosa at the fetal implantation site (the decidua basalis), where maternal and fetal cells are in close contact. Toll-like receptors (TLRs) may play an important role in initiating rapid immune responses against pathogens in the decidua basalis, however the tolerant microenvironment should be preserved in order to allow fetal development. Here we investigated the expression and functionality of TL...

  13. Effect of Chlamydia pneumoniae on Cellular ATP Content in Mouse Macrophages: Role of Toll-Like Receptor 2

    Yaraei, Kambiz; Campbell, Lee Ann; Zhu, Xiaodong; Liles, W. Conrad; Kuo, Cho-chou; Rosenfeld, Michael E.

    2005-01-01

    Chlamydiae are obligate intracellular gram-negative bacteria and are dependent on the host cell for ATP. Thus, chlamydial infection may alter the intracellular levels of ATP and affect all energy-dependent processes within the cell. We have shown that both live C. pneumoniae and inactivated C. pneumoniae induce markers of cell death prior to completion of the bacterial growth cycle. As depletion of ATP could account for the observed increase in cell death, the effects of C. pneumoniae on ATP concentrations within mouse macrophages were investigated. Live, heat-killed, and UV-inactivated C. pneumoniae cultures (at multiplicities of infection [MOIs] of 0.01, 0.1, and 1.0) were incubated with mouse bone marrow macrophages isolated from C57BL/6J mice and mice deficient in Toll-like receptors. Treatment of the macrophages with both live and inactivated C. pneumoniae increased the ATP content of the cells. In cells infected with live C. pneumoniae, the increase was inversely proportional to the MOI. In cells treated with inactivated C. pneumoniae, the increase in ATP content was smaller than that induced by infection with live organisms and was proportional to the MOI. The increase in ATP content early in the developmental cycle was independent of the growth of C. pneumoniae, while sustained induction required live organisms. The capacity of C. pneumoniae to increase the ATP content was ablated in macrophages deficient in expression of either Toll-like receptor 2 or the Toll-like receptor accessory protein MyD88. In contrast, no effect was observed in macrophages lacking expression of Toll-like receptor 4. PMID:15972526

  14. A novel model of common Toll-like receptor 4- and injury-induced transcriptional themes in human leukocytes

    Haimovich, Beatrice; Reddell, Michael T; Calvano, Jacqueline E; Calvano, Steve E.; Macor, Marie A; Coyle, Susette M.; Lowry, Stephen F.

    2010-01-01

    Introduction An endotoxin challenge, sepsis, and injury/trauma, trigger significant changes in human peripheral blood leukocytes (PBL) gene expression. In this study, we have sought to test the hypothesis that the Toll-like receptor 4 (TLR4) induced transcription patterns elicited in humans exposed to in vivo endotoxin would parallel gene expression patterns observed in trauma patients with initial non-infectious injury. In addition, we sought to identify functional modules that are commonly ...

  15. Chronic Restraint Stress Promotes Immune Suppression through Toll-like Receptor 4-Mediated Phosphoinositide 3-kinase Signaling

    Zhang, Yi; Zhang, Ying; Miao, JunYing; Hanley, Gregory; Stuart, Charles; Sun, Xiuli; Chen, Tingting; Yin, Deling

    2008-01-01

    Stress, either psychological or physical, can have a dramatic impact on the immune system. Toll-like receptors (TLRs) play a pivotal role in the induction of innate and adaptive immune response. We have reported that stress modulates the immune response in a TLR4-dependent manner. However, the mechanisms underlying TLR4-mediated signaling in stress modulation of immune system have not been identified. Here, we demonstrate an essential role for the TLR4-mediated phosphoinositide 3-kinase (PI3K...

  16. CD4+ T Cells and Toll-Like Receptors Recognize Salmonella Antigens Expressed in Bacterial Surface Organelles

    Bergman, Molly A.; Cummings, Lisa A.; Barrett, Sara L. Rassoulian; Smith, Kelly D.; Lara, J. Cano; Aderem, Alan; Cookson, Brad T.

    2005-01-01

    A better understanding of immunity to infection is revealed from the characteristics of microbial ligands recognized by host immune responses. Murine infection with the intracellular bacterium Salmonella generates CD4+ T cells that specifically recognize Salmonella proteins expressed in bacterial surface organelles such as flagella and membrane vesicles. These natural Salmonella antigens are also ligands for Toll-like receptors (TLRs) or avidly associated with TLR ligands such as lipopolysacc...

  17. Colonic mucosal DNA methylation, immune response, and microbiome patterns in Toll-like receptor 2-knockout mice

    Kellermayer, Richard; Dowd, Scot E.; Harris, R. Alan; Balasa, Alfred; Schaible, Tiffany D.; Wolcott, Randy D; Tatevian, Nina; Szigeti, Reka; Li, Zhijie; Versalovic, James; Smith, C. Wayne

    2011-01-01

    The connection between intestinal microbiota and host physiology is increasingly becoming recognized. The details of this dynamic interaction, however, remain to be explored. Toll-like receptor 2 (Tlr2) is important for its role in bacterial recognition, intestinal inflammation, and obesity-related metabolic changes. Therefore, we sought to determine the epigenomic and metagenomic consequences of Tlr2 deficiency in the colonic mucosa of mice to gain insights into biological pathways that shap...

  18. Association of Toll-like receptor 4 (TLR4) with chronic plaque type psoriasis and psoriatic arthritis.

    Smith, RL; Hébert, HL; Massey, J; Bowes, J; Marzo-Ortega, H; Ho, P.; McHugh, NJ; Worthington, J; A. BARTON; Griffiths, CE; Warren, RB

    2016-01-01

    Family studies have provided overwhelming evidence for an underlying genetic component to psoriasis. Toll-like receptors (TLRs) are key transmembrane proteins in both the innate and adaptive immune responses which are known to be integral processes in psoriasis. Recent functional studies support this notion having suggested a role for TLR4 in the pathogenesis of psoriasis. Furthermore a missense polymorphism in the TLR4 gene has been associated with a number of autoimmune conditions, includin...

  19. Comparative genomics of Toll-like receptor signalling in five species

    Wu Chunhua

    2009-05-01

    Full Text Available Abstract Background Over the last decade, several studies have identified quantitative trait loci (QTL affecting variation of immune related traits in mammals. Recent studies in humans and mice suggest that part of this variation may be caused by polymorphisms in genes involved in Toll-like receptor (TLR signalling. In this project, we used a comparative approach to investigate the importance of TLR-related genes in comparison with other immunologically relevant genes for resistance traits in five species by associating their genomic location with previously published immune-related QTL regions. Results We report the genomic localisation of TLR1-10 and ten associated signalling molecules in sheep and pig using in-silico and/or radiation hybrid (RH mapping techniques and compare their positions with their annotated homologues in the human, cattle and mouse whole genome sequences. We also report medium-density RH maps for porcine chromosomes 8 and 13. A comparative analysis of the positions of previously published relevant QTLs allowed the identification of homologous regions that are associated with similar health traits in several species and which contain TLR related and other immunologically relevant genes. Additional evidence was gathered by examining relevant gene expression and association studies. Conclusion This comparative genomic approach identified eight genes as potentially causative genes for variations of health related traits. These include susceptibility to clinical mastitis in dairy cattle, general disease resistance in sheep, cattle, humans and mice, and tolerance to protozoan infection in cattle and mice. Four TLR-related genes (TLR1, 6, MyD88, IRF3 appear to be the most likely candidate genes underlying QTL regions which control the resistance to the same or similar pathogens in several species. Further studies are required to investigate the potential role of polymorphisms within these genes.

  20. Trichostatin A Protects Liver against Septic Injury through Inhibiting Toll-Like Receptor Signaling.

    Kim, So-Jin; Park, Jin-Sook; Lee, Do-Won; Lee, Sun-Mee

    2016-07-01

    Sepsis, a serious clinical problem, is characterized by a systemic inflammatory response to infection and leads to organ failure. Toll-like receptor (TLR) signaling is intimately implicated in hyper-inflammatory responses and tissue injury during sepsis. Histone deacetylase (HDAC) inhibitors have been reported to exhibit anti-inflammatory properties. The aim of this study was to investigate the hepatoprotective mechanisms of trichostatin A (TSA), a HDAC inhibitor, associated with TLR signaling pathway during sepsis. The anti-inflammatory properties of TSA were assayed in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Polymicrobial sepsis was induced in mice by cecal ligation and puncture (CLP), a clinically relevant model of sepsis. The mice were intraperitoneally received TSA (1, 2 or 5 mg/kg) 30 min before CLP. The serum and liver samples were collected 6 and 24-h after CLP. TSA inhibited the increased production of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in LPS-stimulated RAW264.7 cells. TSA improved sepsis-induced mortality, attenuated liver injury and decreased serum TNF-α and IL-6 levels. CLP increased the levels of TLR4, TLR2 and myeloid differentiation primary response protein 88 (MyD88) protein expression and association of MyD88 with TLR4 and TLR2, which were attenuated by TSA. CLP increased nuclear translocation of nuclear factor kappa B and decreased cytosolic inhibitor of kappa B (IκB) protein expression, which were attenuated by TSA. Moreover, CLP decreased acetylation of IκB kinase (IKK) and increased association of IKK with IκB and TSA attenuated these alterations. Our findings suggest that TSA attenuates liver injury by inhibiting TLR-mediated inflammatory response during sepsis. PMID:27068262

  1. Neutrophil transepithelial migration: role of toll-like receptors in mucosal inflammation

    Titus A Reaves

    2005-03-01

    Full Text Available The symptomatic phases of many inflammatory diseases are characterized by migration of large numbers of neutrophils (PMN across a polarized epithelium and accumulation within a lumen. For example, acute PMN influx is common in diseases of the gastrointestinal system (ulcerative colitis, Crohn's disease, bacterial enterocolitis, gastritis, hepatobiliary system (cholangitis, acute cholecystitis, respiratory tract (bronchial pneumonia, bronchitis, cystic fibrosis, bronchiectasis, and urinary tract (pyelonephritis, cystitis. Despite these observations, the molecular basis of leukocyte interactions with epithelial cells is incompletely understood. In vitro models of PMN transepithelial migration typically use N-formylated bacterial peptides such as fMLP in isolation to drive human PMNs across epithelial monolayers. However, other microbial products such as lipopolysaccharide (LPS are major constituents of the intestinal lumen and have potent effects on the immune system. In the absence of LPS, we have shown that transepithelial migration requires sequential adhesive interactions between the PMN beta2 integrin CD11b/CD18 and JAM protein family members. Other epithelial ligands appear to be abundantly represented as fucosylated proteoglycans. Further studies indicate that the rate of PMN migration across mucosal surfaces can be regulated by the ubiquitously expressed transmembrane protein CD47 and microbial-derived factors, although many of the details remain unclear. Current data suggests that Toll-like receptors (TLR, which recognize specific pathogen-associated molecular patterns (PAMPs, are differentially expressed on both leukocytes and mucosal epithelial cells while serving to modulate leukocyte-epithelial interactions. Exposure of epithelial TLRs to microbial ligands has been shown to result in transcriptional upregulation of inflammatory mediators whereas ligation of leukocyte TLRs modulate specific antimicrobial responses. A better

  2. Monocyte Toll-Like Receptor Expression in Patients With Atrial Fibrillation.

    Gurses, Kadri Murat; Kocyigit, Duygu; Yalcin, Muhammed Ulvi; Canpinar, Hande; Yorgun, Hikmet; Sahiner, Mehmet Levent; Kaya, Ergun Baris; Oto, Mehmet Ali; Ozer, Necla; Guc, Dicle; Aytemir, Kudret

    2016-05-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia. Inflammation has been suggested to play a vital role in the pathogenesis. Previous studies have investigated expression of inflammatory markers in AF. Several studies have focused on the effects of toll-like receptors (TLRs) on heart in terms of capability of modulating inflammation. In this study, we aimed to investigate whether peripheral monocyte TLR expression was associated with the AF presence, and recurrence of AF after cryoablation, as a reflection of inflammatory status. Patients with AF who were scheduled for cryoballoon-based ablation for AF and age- and gender-matched subjects in sinus rhythm were included. Peripheral monocyte TLR-2 and TLR-4 expressions were evaluated by flow cytometric analysis in peripheral venous blood samples obtained during evaluation in outpatient clinics: 172 patients (56.5 ± 6.6 years, 52.3% men) were included in the study. Peripheral monocyte TLR-2 and TLR-4 expression levels were significantly higher in patients with AF (p analysis showed that left atrial volume index (hazard ratio 2.040, 95% CI 1.197 to 3.477, p = 0.009) and monocyte TLR-4 expression (hazard ratio 1.226, 95% CI 1.042 to 1.443, p = 0.014) were independent predictors of AF recurrence after blanking period following second-generation cryoballoon-based pulmonary vein isolation for paroxysmal AF. In conclusion, our study highlights the role of TLR-mediated inflammation in the pathogenesis of AF. This link may also constitute a therapeutic target in patients with AF. PMID:26988292

  3. Systemic Toll-like receptor stimulation suppresses experimental allergic asthma and autoimmune diabetes in NOD mice.

    Aude Aumeunier

    Full Text Available BACKGROUND: Infections may be associated with exacerbation of allergic and autoimmune diseases. Paradoxically, epidemiological and experimental data have shown that some microorganisms can also prevent these pathologies. This observation is at the origin of the hygiene hypothesis according to which the decline of infections in western countries is at the origin of the increased incidence of both Th1-mediated autoimmune diseases and Th2-mediated allergic diseases over the last decades. We have tested whether Toll-like receptor (TLR stimulation can recapitulate the protective effect of infectious agents on allergy and autoimmunity. METHODS AND FINDINGS: Here, we performed a systematic study of the disease-modifying effects of a set of natural or synthetic TLR agonists using two experimental models, ovalbumin (OVA-induced asthma and spontaneous autoimmune diabetes, presenting the same genetic background of the non obese diabetic mouse (NOD that is highly susceptible to both pathologies. In the same models, we also investigated the effect of probiotics. Additionally, we examined the effect of the genetic invalidation of MyD88 on the development of allergic asthma and spontaneous diabetes. We demonstrate that multiple TLR agonists prevent from both allergy and autoimmunity when administered parenterally. Probiotics which stimulate TLRs also protect from these two diseases. The physiological relevance of these findings is further suggested by the major acceleration of OVA-induced asthma in MyD88 invalidated mice. Our results strongly indicate that the TLR-mediated effects involve immunoregulatory cytokines such as interleukin (IL-10 and transforming growth factor (TGF-beta and different subsets of regulatory T cells, notably CD4+CD25+FoxP3+ T cells for TLR4 agonists and NKT cells for TLR3 agonists. CONCLUSIONS/SIGNIFICANCE: These observations demonstrate that systemic administration of TLR ligands can suppress both allergic and autoimmune responses

  4. Toll-Like Receptor 4 Signaling Pathway Mediates Inhalant Organic Dust-Induced Bone Loss.

    Staab, Elizabeth; Thiele, Geoffrey M; Clarey, Dillon; Wyatt, Todd A; Romberger, Debra J; Wells, Adam D; Dusad, Anand; Wang, Dong; Klassen, Lynell W; Mikuls, Ted R; Duryee, Michael J; Poole, Jill A

    2016-01-01

    Agriculture workers have increased rates of airway and skeletal disease. Inhalant exposure to agricultural organic dust extract (ODE) induces bone deterioration in mice; yet, mechanisms underlying lung-bone crosstalk remain unclear. Because Toll-like receptor 2 (TLR2) and TLR4 are important in mediating the airway consequences of ODE, this study investigated their role in regulating bone responses. First, swine facility ODE stimulated wild-type (WT) bone marrow macrophages to form osteoclasts, and this finding was inhibited in TLR4 knock-out (KO), but not TLR2 KO cells. Next, using an established intranasal inhalation exposure model, WT, TLR2 KO and TLR4 KO mice were treated daily with ODE or saline for 3 weeks. ODE-induced airway neutrophil influx and cytokine/chemokine release were similarly reduced in TLR2 and TLR4 KO animals as compared to WT mice. Utilizing micro-computed tomography (CT), analysis of tibia showed loss of bone mineral density, volume and deterioration of bone micro-architecture and mechanical strength induced by ODE in WT mice were significantly reduced in TLR4 but not TLR2 KO animals. Bone marrow osteoclast precursor cell populations were analyzed by flow cytometry from exposed animals. In WT animals, exposure to inhalant ODE increased osteoclast precursor cell populations as compared to saline, an effect that was reduced in TLR4 but not TLR2 KO mice. These results show that TLR2 and TLR4 pathways mediate ODE-induced airway inflammation, but bone deterioration consequences following inhalant ODE treatment is strongly dependent upon TLR4. Thus, the TLR4 signaling pathway appears critical in regulating the lung-bone inflammatory axis to microbial component-enriched organic dust exposures. PMID:27479208

  5. Toll-like receptors, chemokine receptors and death receptor ligands responses in SARS coronavirus infected human monocyte derived dendritic cells

    Law Helen KW

    2009-06-01

    Full Text Available Abstract Background The SARS outbreak in 2003 provides a unique opportunity for the study of human responses to a novel virus. We have previously reported that dendritic cells (DCs might be involved in the immune escape mechanisms for SARS-CoV. In this study, we focussed on the gene expression of toll-like receptors (TLRs, chemokine receptors (CCRs and death receptor ligands in SARS-CoV infected DCs. We also compared adult and cord blood (CB DCs to find a possible explanation for the age-dependent severity of SARS. Results Our results demonstrates that SARS-CoV did not modulate TLR-1 to TLR-10 gene expression but significantly induced the expression of CCR-1, CCR-3, and CCR-5. There was also strong induction of TNF-related apoptosis-inducing ligand (TRAIL, but not Fas ligand gene expression in SARS-CoV infected DCs. Interestingly, the expressions of most genes studied were higher in CB DCs than adult DCs. Conclusion The upregulation of chemokines and CCRs may facilitate DC migration from the infection site to the lymph nodes, whereas the increase of TRAIL may induce lymphocyte apoptosis. These findings may explain the increased lung infiltrations and lymphoid depletion in SARS patients. Further explorations of the biological significance of these findings are warranted.

  6. Dependence of Bacterial Protein Adhesins on Toll-Like Receptors for Proinflammatory Cytokine Induction

    Hajishengallis, George; Martin, Michael; Sojar, Hakimuddin T.; Sharma, Ashu; Schifferle, Robert E.; DeNardin, Ernesto; Russell, Michael W.; Genco, Robert J.

    2002-01-01

    Toll-like receptors (TLRs) are important signal transducers that mediate inflammatory reactions induced by microbes through pattern recognition of virulence molecules such as lipopolysaccharide (LPS) and lipoproteins. We investigated whether proinflammatory cytokine responses induced by certain bacterial protein adhesins may also depend on TLRs. In differentiated THP-1 mononuclear cells stimulated by LPS-free recombinant fimbrillin (rFimA) from Porphyromonas gingivalis, cytokine release was abrogated by monoclonal antibodies (MAbs) to CD14 and TLR4 but not to TLR2. Similar experiments using anti-β2 integrin MAbs suggested that β2 integrins (CD11/CD18) also play a role in cytokine induction by rFimA or native fimbriae. Minor fimbriae (distinct from the fimA-encoded major fimbriae) of P. gingivalis induced proinflammatory cytokine release in a CD14- and TLR2-dependent mode. Cytokine induction by BspA, a leucine-rich repeat protein from Bacteroides forsythus, depended heavily on CD14 and TLR2. We also found that the ability of the streptococcal protein AgI/II to stimulate cytokine release depended partially on CD14 and TLR4, and the AgI/II segment that possibly interacts with these receptors was identified as its N-terminal saliva-binding region. When THP-1 cells were exposed to rFimA for 24 h, surface expression of CD14 and CD18 was decreased and the cells became hyporesponsive to cytokine induction by a second challenge with rFimA. However, tolerance induction was abolished when the THP-1 cells were pretreated with rFimA in the presence of either anti-CD14 MAb or anti-TLR4 MAb. Induction of cross-tolerance between rFimA and LPS correlated with downregulation of the pattern recognition receptors involved. Our data suggest that the CD14-TLR2/4 system is involved in cytokine production and tolerance induction upon interaction with certain proinflammatory bacterial protein adhesins. PMID:11874886

  7. Stimulation of Toll-like receptor-1/2 combined with Velcade increases cytotoxicity to human multiple myeloma cells

    An increasing body of evidence supports the important role of adhesion to bone marrow microenvironment components for survival and drug resistance of multiple myeloma (MM) cells. Previous studies suggested that stimulation of Toll-like receptors by endogenous ligands released during inflammation and tissue damage may be pro-tumorigenic, but no studies have been performed in relation to modulation of cell adhesion and drug cytotoxicity. Here, we investigated the effect of TLR1/2 activation on adhesion of human myeloma cells to fibronectin, and their sensitivity to the proteasome inhibitor Velcade. It was found that TLR1/2 activation with Pam3CSK4 increased the cytotoxicity of Velcade in L363, OPM-2 and U266 human myeloma cells. This effect was not related to a decreased adhesion of the cells to fibronectin, but TLR1/2 activation stimulated the caspase-3 activity in Velcade-treated myeloma cells, which may be responsible for the enhanced cell death. Inhibitors of NF-κB and MAPK reduced the stimulatory effect. These findings indicate that TLR activation of MM cells could bypass protective effects of cell adhesion and suggest that TLR signaling may also have antitumorigenic potential

  8. Protective Role of Toll-like Receptor 3-Induced Type I Interferon in Murine Coronavirus Infection of Macrophages

    Sonia Navas-Martin

    2012-05-01

    Full Text Available Toll-like Receptors (TLRs sense viral infections and induce production of type I interferons (IFNs, other cytokines, and chemokines. Viral recognition by TLRs and other pattern recognition receptors (PRRs has been proven to be cell-type specific. Triggering of TLRs with selected ligands can be beneficial against some viral infections. Macrophages are antigen-presenting cells that express TLRs and have a key role in the innate and adaptive immunity against viruses. Coronaviruses (CoVs are single-stranded, positive-sense RNA viruses that cause acute and chronic infections and can productively infect macrophages. Investigation of the interplay between CoVs and PRRs is in its infancy. We assessed the effect of triggering TLR2, TLR3, TLR4, and TLR7 with selected ligands on the susceptibility of the J774A.1 macrophage cell line to infection with murine coronavirus (mouse hepatitis virus, [MHV]. Stimulation of TLR2, TLR4, or TLR7 did not affect MHV production. In contrast, pre-stimulation of TLR3 with polyinosinic-polycytidylic acid (poly I:C hindered MHV infection through induction of IFN-β in macrophages. We demonstrate that activation of TLR3 with the synthetic ligand poly I:C mediates antiviral immunity that diminishes (MHV-A59 or suppresses (MHV-JHM, MHV-3 virus production in macrophages.

  9. Effects of human Toll-like receptor 1 polymorphisms on ageing

    Uciechowski Peter

    2013-02-01

    Full Text Available Abstract Background Advanced age results in crucial alterations of the innate and adaptive immune system leading to functional defects resulting in infection and chronic diseases. Toll-like receptors (TLR recognize pathogenic structures and are important in the immune response to infections and vaccination. However, the role of TLR single nucleotide polymorphisms (SNP is poorly understood in the setting of human ageing. This study investigated the impact of the TLR1 SNPs A743G and T1805G on ageing in different age groups from two European populations. Results The TLR1 genotypes 743AA/1805GG (TLR1neg are associated with a TLR1 negative phenotype, impaired function and susceptibility to tuberculosis. Carriers of heterozygous 743AG/1805TG and homozygous 743GG/1805TT genotypes (TLR1pos have a TLR1 positive phenotype. By comparing healthy young and old German donors, the old group showed a tendency to carry more TLR1neg and less homozygous TLR1pos genotypes. Anti-inflammatory Interleukin (IL-1 receptor antagonist (Ra was significantly elevated in supernatants of mononuclear cells from old German subjects with a TLR1pos genotype in contrast to those with the 743AA genotype. Healthy old individuals and nonagenarians from Italy displayed significantly higher frequencies of TLR1pos genotypes than the old group from Germany. The data show that tumor-necrosis-factor (TNFα, CXCL8 and CCL2 levels were higher in old donors from Germany than in plasma levels from old Italian donors. TNFα and CCL2 levels were significantly raised in old German individuals compared to Italian nonagenarians. German and Italian donors with the TLR1neg genotype basically produced more CCL2 than older European donors with TLR1pos genotypes. Conclusion The higher frequency of the TLR1pos genotype in elderly Italian subjects may result from different ethnic populations. Lower inflammatory mediator release of aged Italian individuals is probably due to different background in

  10. An Oligomeric Signaling Platform Formed by the Toll-like Receptor Signal Transducers MyD88 and IRAK-4*

    Motshwene, Precious G.; Moncrieffe, Martin C.; Grossmann, J. Günter; KAO, CHENG; Ayaluru, Murali; Sandercock, Alan M.; Carol V Robinson; Latz, Eicke; Gay, Nicholas J.

    2009-01-01

    Toll-like receptors (TLRs) mediate responses to pathogen-associated molecules as part of the vertebrate innate immune response to infection. Receptor dimerization is coupled to downstream signal transduction by the recruitment of a post-receptor complex containing the adaptor protein MyD88 and the IRAK protein kinases. In this work, we show that the death domains of human MyD88 and IRAK-4 assemble into closed complexes having unusual stoichiometries of 7:4 and 8:4, the Myddosome. Formation of...

  11. Variant Toll-Like Receptor4 (Asp299Gly and Thr399Ile Alleles) and Toll-Like Receptor2 (Arg753Gln and Arg677Trp Alleles) in Colorectal Cancer

    Homa Davoodi; Fong Seow

    2011-01-01

    The innate immune system recognizes the presence of bacterial products through the expression of a family of membrane receptors known as Toll-like receptors (TLRs). Polymorphisms in TLRs have been shown to be associated with increased susceptibility to diseases such as inflammatory bowel disease.The aim of this study was to determine whether there was a correlation between polymorphisms of TLR4 (Asp299Gly; Thr399Ile) and TLR2 (Arg677Trp; Arg753Gln) genes and risk of colorectal cancer. DNA fro...

  12. Variant Toll-Like Receptor4 (Asp299Gly and Thr399Ile Alleles) and Toll-Like Receptor2 (Arg753Gln and Arg677Trp Alleles) in Colorectal Cancer

    Fong Seow; Homa Davoodi

    2011-01-01

    The innate immune system recognizes the presence of bacterial products through the expression of a family of membrane receptors known as Toll-like receptors (TLRs). Polymorphisms in TLRs have been shown to be associated with increased susceptibility to diseases such as inflammatory bowel disease. The aim of this study was to determine whether there was a correlation between polymorphisms of TLR4 (Asp299Gly; Thr399Ile) and TLR2 (Arg677Trp; Arg753Gln) genes and risk of colorectal cancer. DNA fr...

  13. The repertoire for pattern recognition of pathogens by the innate immune system is defined by cooperation between Toll-like receptors

    Ozinsky, Adrian; Underhill, David M; Fontenot, Jason D.; Adeline M Hajjar; Smith, Kelly D.; Wilson, Christopher B.; Schroeder, Lea; Aderem, Alan

    2000-01-01

    Toll-like receptors (TLRs) have been shown to participate in the recognition of pathogens by the innate immune system, but it is not clear how a restricted family of receptors has the capacity to recognize the wide spectrum of TLR stimuli known to exist. We report here that two members of the TLR family, TLR2 and TLR6, together coordinate macrophage activation by Gram-positive bacteria and the yeast cell-wall particle, zymosan. TLR6 and TLR2 both are recruited to t...

  14. Evidence for possible role of toll-like receptor 3 mediating virus-induced progression of pituitary adenomas.

    Zheng, Xin; Li, Song; Zang, Zhenle; Hu, Jintao; An, Jiayin; Pei, Xiangdong; Zhu, Feng; Zhang, Weihua; Yang, Hui

    2016-05-01

    Tumor-related viruses are known to be involved in initiation and progression of certain tumors. However, the relationship between virus and pituitary adenomas (PAs) remains unknown. Here, we investigated infection status of three types of viruses (HPV16, HHV6B and HSV1) and expression level of toll-like receptor 3 (TLR3) in 60 human PA samples. We also determined the role of TLR3 signaling pathway on a PA cell line (GH3). We firstly found that positive rates of HPV16 and HHV6B infection were significantly higher in invasive PA samples than in noninvasive samples (P < 0.01). Similarly, TLR3 mRNA and protein expression also increased in invasive PA samples (P < 0.01). In vitro analysis indicated that GH3 cell proliferation and survival were enhanced by TLR3 activation, which was accompanied by NF-κB activation. Our data indicate that HPV16 and HHV6B viruses may be involved in promoting the progression of PA by activating the TLR3 signaling pathway. PMID:26891958

  15. Lactobacillus casei prevents the development of dextran sulphate sodium-induced colitis in Toll-like receptor 4 mutant mice.

    Chung, Y W; Choi, J H; Oh, T-Y; Eun, C S; Han, D S

    2008-01-01

    Probiotics, defined as live or attenuated bacteria or bacterial products, confer a significant health benefit to the host. Recently, they have been shown to be useful in the treatment of chronic inflammatory bowel disease and infectious colitis. In this study, we investigated the effect of probiotics on the development of experimental colitis using Toll-like receptor 4 (TLR-4) mutant (lps-/lps-) mice. TLR-4(lps-/lps-) and wild-type (WT) mice were given 2.5% dextran sulphate sodium (DSS) in drinking water to induce colitis with or without Lactobacillus casei pretreatment. Clinical and histological activity of DSS-colitis was attenuated markedly both in TLR-4(lps-/lps-) and WT mice pretreated with L. casei. Interestingly, histological activity was less severe in TLR-4(lps-/lps-) mice than in WT mice. The levels of myeloperoxidase activity and interleukin (IL)-12p40 were attenuated in pretreated TLR-4(lps-/lps-) mice after DSS administration. By contrast, transforming growth factor (TGF)-beta and IL-10 mRNA and protein expressions were increased markedly in pretreated TLR-4(lps-/lps-) mice. The current results suggest that L. casei has a preventive effect in the development of acute DSS-induced colitis and its action depends largely upon TLR-4 status. L. casei modulates the expression of inflammatory cytokines and down-regulates neutrophilic infiltration in the case of incomplete TLR-4 complex signalling. PMID:18005362

  16. Herpes simplex virus infection is sensed by both Toll-like receptors and retinoic acid-inducible gene- like receptors, which synergize to induce type I interferon production

    Rasmussen, Simon Brandtoft; Jensen, Søren B; Nielsen, C;

    2009-01-01

    The innate antiviral response is initiated by pattern recognition receptors, which recognize viral pathogen-associated molecular patterns. Here we show that retinoic acid-inducible gene (RIG)-I-like receptors (RLRs) in cooperation with Toll-like receptor (TLR) 9 is required for expression of type I...

  17. Downstream Toll-like receptor signaling mediates adaptor-specific cytokine expression following focal cerebral ischemia

    Bolanle Famakin

    2012-07-01

    Full Text Available Abstract Background Deletion of some Toll-like receptors (TLRs affords protection against cerebral ischemia, but disruption of their known major downstream adaptors does not. To determine whether compensation in the production of downstream effectors by one pathway when the other is disrupted can explain these findings, we examined cytokine/chemokine expression and inflammatory infiltrates in wild-type (WT, MyD88−/− and TRIF-mutant mice following permanent middle cerebral artery occlusion (pMCAO. Methods Cytokine/chemokine expression was measured with a 25-plex bead array in the serum and brains of all three groups of mice at baseline (no surgery/naïve and at 3 hours and 24 hours following pMCAO. Brain inflammatory and neutrophil infiltrates were examined 24 hours following pMCAO. Results IL-6, keratinocyte chemoattractant (KC, granulocyte colony-stimulating factor (G-CSF and IL-10 were significantly decreased in MyD88−/− mice compared to WT mice following pMCAO. Significantly, decreased levels of the neutrophil chemoattractants KC and G-CSF corresponded with a trend toward fewer neutrophils in the brains of MyD88−/− mice. IP-10 was significantly decreased when either pathway was disrupted. MIP-1α was significantly decreased in TRIF-mutant mice, consistent with TRIF-dependent production. MyD88−/− mice showed elevations of a number of Th2 cytokines, such as IL-13, at baseline, which became significantly decreased following pMCAO. Conclusions Both MyD88 and TRIF mediate pathway-specific cytokine production following focal cerebral ischemia. Our results also suggest a compensatory Th2-type skew at baseline in MyD88−/− mice and a paradoxical switch to a Th1 phenotype following focal cerebral ischemia. The MyD88 pathway directs the expression of neutrophil chemoattractants following cerebral ischemia.

  18. The Toll-Like Receptor 5 Agonist Entolimod Mitigates Lethal Acute Radiation Syndrome in Non-Human Primates.

    Krivokrysenko, Vadim I; Toshkov, Ilia A; Gleiberman, Anatoli S; Krasnov, Peter; Shyshynova, Inna; Bespalov, Ivan; Maitra, Ratan K; Narizhneva, Natalya V; Singh, Vijay K; Whitnall, Mark H; Purmal, Andrei A; Shakhov, Alexander N; Gudkov, Andrei V; Feinstein, Elena

    2015-01-01

    There are currently no approved medical radiation countermeasures (MRC) to reduce the lethality of high-dose total body ionizing irradiation expected in nuclear emergencies. An ideal MRC would be effective even when administered well after radiation exposure and would counteract the effects of irradiation on the hematopoietic system and gastrointestinal tract that contribute to its lethality. Entolimod is a Toll-like receptor 5 agonist with demonstrated radioprotective/mitigative activity in rodents and radioprotective activity in non-human primates. Here, we report data from several exploratory studies conducted in lethally irradiated non-human primates (rhesus macaques) treated with a single intramuscular injection of entolimod (in the absence of intensive individualized supportive care) administered in a mitigative regimen, 1-48 hours after irradiation. Following exposure to LD50-70/40 of radiation, injection of efficacious doses of entolimod administered as late as 25 hours thereafter reduced the risk of mortality 2-3-fold, providing a statistically significant (Pdrug delivered 48 hours after irradiation. Improved survival was accompanied by predominantly significant (P<0.05) effects of entolimod administration on accelerated morphological recovery of hematopoietic and immune system organs, decreased severity and duration of thrombocytopenia, anemia and neutropenia, and increased clonogenic potential of the bone marrow compared to control irradiated animals. Entolimod treatment also led to reduced apoptosis and accelerated crypt regeneration in the gastrointestinal tract. Together, these data indicate that entolimod is a highly promising potential life-saving treatment for victims of radiation disasters. PMID:26367124

  19. The Toll-Like Receptor 5 Agonist Entolimod Mitigates Lethal Acute Radiation Syndrome in Non-Human Primates

    Krivokrysenko, Vadim I.; Toshkov, Ilia A.; Gleiberman, Anatoli S.; Krasnov, Peter; Shyshynova, Inna; Bespalov, Ivan; Maitra, Ratan K.; Narizhneva, Natalya V.; Singh, Vijay K.; Whitnall, Mark H.; Purmal, Andrei A.; Shakhov, Alexander N.; Gudkov, Andrei V.; Feinstein, Elena

    2015-01-01

    There are currently no approved medical radiation countermeasures (MRC) to reduce the lethality of high-dose total body ionizing irradiation expected in nuclear emergencies. An ideal MRC would be effective even when administered well after radiation exposure and would counteract the effects of irradiation on the hematopoietic system and gastrointestinal tract that contribute to its lethality. Entolimod is a Toll-like receptor 5 agonist with demonstrated radioprotective/mitigative activity in rodents and radioprotective activity in non-human primates. Here, we report data from several exploratory studies conducted in lethally irradiated non-human primates (rhesus macaques) treated with a single intramuscular injection of entolimod (in the absence of intensive individualized supportive care) administered in a mitigative regimen, 1–48 hours after irradiation. Following exposure to LD50-70/40 of radiation, injection of efficacious doses of entolimod administered as late as 25 hours thereafter reduced the risk of mortality 2-3-fold, providing a statistically significant (Padministration on accelerated morphological recovery of hematopoietic and immune system organs, decreased severity and duration of thrombocytopenia, anemia and neutropenia, and increased clonogenic potential of the bone marrow compared to control irradiated animals. Entolimod treatment also led to reduced apoptosis and accelerated crypt regeneration in the gastrointestinal tract. Together, these data indicate that entolimod is a highly promising potential life-saving treatment for victims of radiation disasters. PMID:26367124

  20. Toll-Like Receptor Mediated Modulation of T Cell Response by Commensal Intestinal Microbiota as a Trigger for Autoimmune Arthritis

    Rebecca Rogier

    2015-01-01

    Full Text Available In autoimmune diseases, a disturbance of the balance between T helper 17 (Th17 and regulatory T cells (Tregs is often observed. This disturbed balance is also the case in rheumatoid arthritis (RA. Genetic predisposition to RA confers the presence of several polymorphisms mainly regulating activation of T lymphocytes. However, the presence of susceptibility factors is neither necessary nor sufficient to explain the disease development, emphasizing the importance of environmental factors. Multiple studies have shown that commensal gut microbiota is of great influence on immune homeostasis and can trigger the development of autoimmune diseases by favoring induction of Th17 cells over Tregs. However the mechanism by which intestinal microbiota influences the Th cell balance is not completely understood. Here we review the current evidence supporting the involvement of commensal intestinal microbiota in rheumatoid arthritis, along with a potential role of Toll-like receptors (TLRs in modulating the relevant Th cell responses to trigger autoimmunity. A better understanding of TLR triggering by intestinal microbiota and subsequent T cell activation might offer new perspectives for manipulating the T cell response in RA patients and may lead to the discovery of new therapeutic targets or even preventive measures.

  1. Maternal Smoking in Pregnancy: Do the Effects on Innate (Toll-Like Receptor Function Have Implications for Subsequent Allergic Disease?

    Prescott Susan L

    2007-03-01

    Full Text Available Subtle increases in immaturity of immune function in early infancy have been implicated in the rising susceptibility to allergic disease, particularly relative impairment of type 1 interferon (IFN-γ responses in the neonatal period. Although genetic predisposition is a clear risk factor, the escalating rates of allergic disease in infancy suggest that environmental factors are also implicated. We previously showed that maternal smoking in pregnancy may impair neonatal IFN-γ responses. Our more recent studies now indicate that this common avoidable toxic exposure is also associated with attenuation of innate immune function, with attenuated Toll-like receptor (TLR-mediated microbial responses (including TLR-2, -3, -4, and -9 responses. Most notably, the effects were more marked if the mothers were also allergic. In this review, we discuss the significance of these observations in the context of the emerging hypothesis that variations in TLR function in early life may be implicated in allergic propensity. There is now growing evidence that many of the key pathways involved in subsequent T-cell programming and regulation (namely, antigen-presenting cells and regulatory T cells rely heavily on microbe-driven TLR activation for maturation and function. Factors that influence the function and activity of these innate pathways in early life may contribute to the increasing predisposition for allergic disease. Although "cleaner" environments have been implicated, here we explore the possibility that other common environmental exposures (such as maternal smoking could also play a role.

  2. An oncolytic adenovirus enhanced for toll-like receptor 9 stimulation increases antitumor immune responses and tumor clearance.

    Cerullo, Vincenzo; Diaconu, Iulia; Romano, Valentina; Hirvinen, Mari; Ugolini, Matteo; Escutenaire, Sophie; Holm, Sirkka-Liisa; Kipar, Anja; Kanerva, Anna; Hemminki, Akseli

    2012-11-01

    Oncolytic viruses represent a multifaceted tool for cancer treatment. In addition to specific killing of cancer cells (oncolysis), these agents also provide danger signals prompting the immune system to stimulate an antitumor immune response. To increase adenovirus adjuvancy, we engineered the genome of Ad5D24 by inserting 18 immunostimulatory islands (Ad5D24-CpG). The toxicity and immunogenicity profile of Ad5D24-CpG showed that the safety of the maternal virus was retained. The efficacy of the CpG-enriched virus was assessed in a xenograft model of lung cancer where a significant increase in antitumor effect was seen in comparison with controls. When the experiment was repeated in animal depleted of natural killer (NK) cells, Ad5D24-CpG lost its advantage. The same was seen when Toll-like receptor (TLR)9 was blocked systemically. In a syngeneic model of melanoma (B16-OVA), we observed a significant increase of OVA-specific T cells and a decrease of activation of myeloid-derived suppressor cells in Ad5D24-CpG-treated mice. In conclusion, we have generated the first genetically modified oncolytic adenovirus backbone able to enhance TLR9-stimulation for increased antitumor activity. PMID:22828500

  3. Vanadate from air pollutant inhibits hrs-dependent endosome fusion and augments responsiveness to toll-like receptors.

    Zelnikar, Mojca; Benčina, Mojca; Jerala, Roman; Manček-Keber, Mateja

    2014-01-01

    There is a well-established association between exposure to air pollutants and pulmonary injuries. For example, metals found in ROFA (residual oil fly ash) increase susceptibility of mice as well as humans to microbial infections. In our research, we have found that vanadate substantially increased the response of several Toll-like receptors (TLRs) to stimulation with their ligands. Although vanadate caused generation of reactive oxygen species (ROS), the addition of ROS scavenger N-acetyl cysteine (NAC) had no effect on augmented lipopolysaccharide (LPS) stimulation. We further showed that vanadate inhibits endosome fusion. This effect was determined by measuring the size of endosomes, NF-κB activity and TLR4 degradation in Hrs (hepatocyte growth factor-regulated tyrosine kinase substrate) overexpressed cells. Moreover, we identified the role of Hrs phosphorylation in these processes. Based on our findings, we can conclude that vanadate potentiates TLR4 activity by increasing Hrs phosphorylation status, reducing the size of Hrs/TLR4-positive endosomes and impacting TLR4 degradation, thus contributing to the detrimental effects of air pollutants on human health. PMID:24901993

  4. DMPD: Critical role of toll-like receptors and nucleotide oligomerisation domain inthe regulation of health and disease. [Dynamic Macrophage Pathway CSML Database

    Full Text Available and nucleotide oligomerisation domain inthe regulation of health and disease. Pu...bmedID 17535871 Title Critical role of toll-like receptors and nucleotide oligomerisation domain inthe regulation of health...17535871 Critical role of toll-like receptors and nucleotide oligomerisation domain inthe regulation of heal...th and disease. Mitchell JA, Paul-Clark MJ, Clarke GW, McMaster SK, Cartwright N. J

  5. Toll-Like Receptor 4 Is an Essential Upstream Regulator of On-Time Parturition and Perinatal Viability in Mice.

    Wahid, Hanan H; Dorian, Camilla L; Chin, Peck Yin; Hutchinson, Mark R; Rice, Kenner C; Olson, David M; Moldenhauer, Lachlan M; Robertson, Sarah A

    2015-10-01

    An inflammatory response is instrumental in the physiological process of parturition but the upstream signals initiating inflammation are undefined. Because endogenous ligands for Toll-like receptor 4 (TLR4) are released in late gestation, we hypothesized that on-time labor requires TLR4 signaling, to trigger a cytokine and leukocyte response and accelerate the parturition cascade. In pregnant TLR4-deficient (Tlr4-/-) mice, average gestation length was extended by 13 hours and increased perinatal mortality was seen compared with wild-type controls. Quantification of cytokine and uterine activation gene expression showed that late gestation induction of Il1b, Il6, Il12b, and Tnf expression seen in control placenta and fetal membranes was disrupted in Tlr4-/- mice, and accompanied by a transient delay in expression of uterine activation genes, including prostaglandin F receptor, oxytocin receptor, and connexin-43. Leukocyte populations were altered before birth in TLR4-deficient females, with fewer neutrophils and macrophages in the placenta, and fewer dendritic cells and more regulatory T cells in the myometrium. Administration of TLR4 ligand lipopolysaccharide to pregnant wild-type mice induced cytokine expression and fetal loss, whereas Tlr4-/- pregnancies were protected. The small molecule TLR4 antagonist (+)-naloxone increased mean duration of gestation by 16 hours in wild-type mice. Collectively, these data demonstrate that TLR4 is a key upstream regulator of the inflammatory response acting to drive uterine activation and control the timing of labor. Because causal pathways for term and preterm labor converge with TLR4, interventions to manipulate TLR4 signaling may have therapeutic utility for women at risk of preterm labor, or in postterm pregnancy. PMID:26151355

  6. Role of the Toll Like receptor (TLR) radical cycle in chronic inflammation: possible treatments targeting the TLR4 pathway.

    Lucas, Kurt; Maes, Michael

    2013-08-01

    Activation of the Toll-like receptor 4 (TLR4) complex, a receptor of the innate immune system, may underpin the pathophysiology of many human diseases, including asthma, cardiovascular disorder, diabetes, obesity, metabolic syndrome, autoimmune disorders, neuroinflammatory disorders, schizophrenia, bipolar disorder, autism, clinical depression, chronic fatigue syndrome, alcohol abuse, and toluene inhalation. TLRs are pattern recognition receptors that recognize damage-associated molecular patterns and pathogen-associated molecular patterns, including lipopolysaccharide (LPS) from gram-negative bacteria. Here we focus on the environmental factors, which are known to trigger TLR4, e.g., ozone, atmosphere particulate matter, long-lived reactive oxygen intermediate, pentachlorophenol, ionizing radiation, and toluene. Activation of the TLR4 pathways may cause chronic inflammation and increased production of reactive oxygen and nitrogen species (ROS/RNS) and oxidative and nitrosative stress and therefore TLR-related diseases. This implies that drugs or substances that modify these pathways may prevent or improve the abovementioned diseases. Here we review some of the most promising drugs and agents that have the potential to attenuate TLR-mediated inflammation, e.g., anti-LPS strategies that aim to neutralize LPS (synthetic anti-LPS peptides and recombinant factor C) and TLR4/MyD88 antagonists, including eritoran, CyP, EM-163, epigallocatechin-3-gallate, 6-shogaol, cinnamon extract, N-acetylcysteine, melatonin, and molecular hydrogen. The authors posit that activation of the TLR radical (ROS/RNS) cycle is a common pathway underpinning many "civilization" disorders and that targeting the TLR radical cycle may be an effective method to treat many inflammatory disorders. PMID:23436141

  7. Upregulation of Toll-like receptor 2 and nuclear factor-kappa B expression in experimental colonic schistosomiasis.

    Ashour, Dalia S; Shohieb, Zeinab S; Sarhan, Naglaa I

    2015-11-01

    Role of different mediators was described in the development of the granulomatous response and fibrosis observed in intestinal schistosomiasis. However, both Toll-like receptor 2 (TLR2) and nuclear factor kappa B (NF-κB) have not yet been investigated in intestinal schistosomiasis. This study aimed to characterize the role of TLR2 and NF-κB in the pathogenesis of intestinal schistosomiasis. Experimental animals were divided into two groups; group I: non-infected control group and group II: mice infected subcutaneously with S. mansoni cercariae. Colon samples were taken from infected mice, every two weeks, starting from the 6th week postinfection (PI) till 18th week PI. Samples were subjected to histopathological and immunohistochemical studies. Colon of S. mansoni infected mice showed histopathological changes in the form of mucosal degeneration, transmural mononuclear cellular infiltration and granulomas formation. Immunostained sections revealed significant increase in TLR2 and NF-κB positive cells in all layers of the colon, cells of the granuloma and those of the lymphoid follicles 10 weeks PI. All these changes decreased gradually starting from 12 weeks PI onward to be localized focally at 18 weeks PI. In conclusion, recruitment and activation of inflammatory cells to the colonic mucosa in intestinal schistosomiasis are multifactorial events involving TLR2 that can trigger the NF-κB pathways. Hence, down-regulation of both TLR2 and NF-κB could be exploited in the treatment of colonic schistosomiasis. PMID:26644925

  8. Toll-like receptor 2 ligand, lipoteichoic acid is inhibitory against infectious laryngotracheitis virus infection in vitro and in vivo.

    Haddadi, S; Thapa, S; Kameka, A M; Hui, J; Czub, M; Nagy, E; Muench, G; Abdul-Careem, M F

    2015-01-01

    Lipoteichoic acid (LTA) is one of the pathogen associated molecular patterns (PAMPs) that activates toll-like receptor (TLR)2-cluster of differentiation (CD)14 signalling pathway. This recognition elicits antiviral responses that have been recorded against viruses of mammals although such responses have not been characterized adequately against avian viruses. In this investigation, we characterized the LTA induced antiviral responses against infectious laryntotracheitis virus (ILTV) infection in vitro and in vivo. We found that LTA is capable of up regulating mRNA expression of innate proteins in macrophages such as MyD88, iNOS and IL-1β and reduces the ILTV plaques in vitro. Similarly, we found that LTA treatment of embryonic day 18 (ED18) eggs can lead to the antiviral response against pre-hatch ILTV infection in vivo and is associated with expansion of macrophage populations and expression of IL-1β and MyD88 in the lung. The data highlight that LTA can be a potential innate immune stimulant that can be used against ILTV infection in chickens. PMID:25195716

  9. Role of Cytokines and Toll-Like Receptors in the Immunopathogenesis of Guillain-Barré Syndrome

    Kishan Kumar Nyati

    2014-01-01

    Full Text Available Guillain-Barré syndrome (GBS is an autoimmune disease of the peripheral nervous system, mostly triggered by an aberrant immune response to an infectious pathogen. Although several infections have been implicated in the pathogenesis of GBS, not all such infected individuals develop this disease. Moreover, infection with a single agent might also lead to different subtypes of GBS emphasizing the role of host factors in the development of GBS. The host factors regulate a broad range of inflammatory processes that are involved in the pathogenesis of autoimmune diseases including GBS. Evidences suggest that systemically and locally released cytokines and their involvement in immune-mediated demyelination and axonal damage of peripheral nerves are important in the pathogenesis of GBS. Toll-like receptors (TLRs link innate and adaptive immunity through transcription of several proinflammatory cytokines. TLR genes may increase susceptibility to microbial infections; an attenuated immune response towards antigen and downregulation of cytokines occurs due to mutation in the gene. Herein, we discuss the crucial role of host factors such as cytokines and TLRs that activate the immune response and are involved in the pathogenesis of the disease.

  10. mRNA-Mediated Gene Supplementation of Toll-Like Receptors as Treatment Strategy for Asthma In Vivo

    Will, Clara; Carevic, Melanie; Rottenberger, Jennifer; Nürnberg, Bernd; Hartl, Dominik; Handgretinger, Rupert; Beer-Hammer, Sandra; Kormann, Michael S. D.

    2016-01-01

    Asthma is the most common chronic disease in childhood. Although several therapeutic options are currently available to control the symptoms, many drugs have significant side effects and asthma remains an incurable disease. Microbial exposure in early life reduces the risk of asthma and several studies have suggested protective effects of Toll-like receptor (TLR) activation. We showed previously that modified mRNA provides a safe and efficient therapeutic tool for in vivo gene supplementation. Since current asthma drugs do not take patient specific immune and TLR backgrounds into consideration, treatment with tailored mRNA could be an attractive approach to account for the patient’s individual asthma phenotype. Therefore, we investigated the effect of a preventative treatment with combinations of Tlr1, Tlr2 and Tlr6 mRNA in a House Dust Mite-induced mouse model of asthma. We used chemically modified mRNA which is–in contrast to conventional viral vectors–non-integrating and highly efficient in gene transfer. In our study, we found that treatment with either Tlr1/2 mRNA or Tlr2/6 mRNA, but not Tlr2 mRNA alone, resulted in better lung function as well as reduced airway inflammation in vivo. The present results point to a potentially protective effect of TLR heterodimers in asthma pathogenesis. PMID:27101288

  11. Downregulation of toll-like receptor 4 and IL-6 following irradiation of the rat urinary bladder.

    Giglio, D; Wasén, C; Mölne, J; Suchy, D; Swanpalmer, J; Jabonero Valbuena, J; Tobin, G; Ny, L

    2016-07-01

    The pathophysiology behind radiation cystitis is poorly understood. Here we investigated whether bladder irradiation affects the immune system of the rat urinary bladder. Female rats were sedated and exposed to one single radiation dose of 20 Gy or only sedated (controls) and killed 16 h to 14 days later. Rats were placed in a metabolic cage at 16 h, 3 days, 7 days and 14 days following bladder irradiation. The urinary bladders were harvested and analysed with qPCR, immunohistochemistry and/or Western blot for the expression of interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, nitric oxide synthases (eNOS, iNOS and nNOS), tumour necrosis factor (TNF)-α and toll-like receptor 4 (TLR4). Urine was collected and analysed for IL-6 and nitrite (reflecting nitric oxide activity) with ELISA and the Griess reaction, respectively. Irradiation increased bladder frequency and decreased voiding volumes 14 days following bladder irradiation. Bladder irradiation increased the expression of IL-10 and collagen in the bladder, while TLR4 and IL-6 expressions were decreased in the urothelium concomitantly with a decrease in mast cells in the submucosa and urine levels of IL-6 and nitrite. The present findings show that bladder irradiation leads to urodynamic changes in the bladder and may suppress important immunoregulatory pathways in the urinary bladder. PMID:27117224

  12. Flagellin-induced tolerance of the Toll-like receptor 5 signaling pathway in polarized intestinal epithelial cells.

    Sun, Jun; Fegan, Pamela E; Desai, Anjali S; Madara, James L; Hobert, Michael E

    2007-03-01

    Salmonella typhimurium is a gram-negative enteric pathogen that invades the mucosal epithelium and is associated with diarrheal illness in humans. Flagellin from S. typhimurium and other gram-negative bacteria has been shown to be the predominant proinflammatory mediator through activation of the basolateral Toll-like receptor 5 (TLR5). Recent evidence has shown that prior exposure can render immune cells tolerant to subsequent challenges by TLR ligands. Accordingly, we examined whether prior exposure to purified flagellin would render human intestinal epithelial cells insensitive to future contact. We found that flagellin-induced tolerance is common to polarized epithelial cells and prevents further activation of proinflammatory signaling cascades by both purified flagellin and Salmonella bacteria but does not affect TNF-alpha stimulation of the same pathways. Flagellin tolerance is a rapid process that does not require protein synthesis, and that occurs within 1 to 2 h of flagellin exposure. Prolonged flagellin exposure blocks activation of the NF-kappaB, MAPK, and phosphoinositol 3-kinase signaling pathways and results in the internalization of a fraction of the basolateral TLR5 without affecting the polarity or total expression of TLR5. After removal of flagellin, cells require more than 24 h to fully recover their ability to mount a normal proinflammatory response. We have found that activation of phosphoinositol 3-kinase and Akt by flagellin has a small damping effect in the early stages of flagellin signaling but is not responsible for tolerance. Our study indicates that inhibition of TLR5-associated IL-1 receptor-associated kinase-4 activity occurs during the development of flagellin tolerance and is likely to be the cause of tolerance. PMID:17138965

  13. A Comparative Analysis of the Mechanism of Toll-Like Receptor-Disruption by TIR-Containing Protein C from Uropathogenic Escherichia coli.

    Waldhuber, Anna; Snyder, Greg A; Römmler, Franziska; Cirl, Christine; Müller, Tina; Xiao, Tsan Sam; Svanborg, Catharina; Miethke, Thomas

    2016-01-01

    The TIR-containing protein C (TcpC) of uropathogenic Escherichia coli strains is a powerful virulence factor by impairing the signaling cascade of Toll-like receptors (TLRs). Several other bacterial pathogens like Salmonella, Yersinia, Staphylococcus aureus but also non-pathogens express similar proteins. We discuss here the pathogenic potential of TcpC and its interaction with TLRs and TLR-adapter proteins on the molecular level and compare its activity with the activity of other bacterial TIR-containing proteins. Finally, we analyze and compare the structure of bacterial TIR-domains with the TIR-domains of TLRs and TLR-adapters. PMID:26938564

  14. The Staphylococcus aureus Lipoprotein SitC Colocalizes with Toll-Like Receptor 2 (TLR2) in Murine Keratinocytes and Elicits Intracellular TLR2 Accumulation ▿ †

    Müller, P; Müller-Anstett, M.; Wagener, J.; Gao, Q.; Kaesler, S.; Schaller, M; Biedermann, T; Götz, F

    2010-01-01

    SitC is one of the predominant lipoproteins in Staphylococcus aureus. Recently, SitC was shown to be capable of stimulating Toll-like receptor 2 (TLR2), but the mechanism of TLR2 activation by SitC has not been analyzed in detail so far. In this study, we purified C-terminally His-tagged SitC (SitC-His) from Staphylococcus aureus. SitC-His induced interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) release in human monocytes and also NF-κB activation in TLR2-transfected HEK293 cells,...

  15. A Comparative Analysis of the Mechanism of Toll-Like Receptor-Disruption by TIR-Containing Protein C from Uropathogenic Escherichia coli

    Anna Waldhuber

    2016-02-01

    Full Text Available The TIR-containing protein C (TcpC of uropathogenic Escherichia coli strains is a powerful virulence factor by impairing the signaling cascade of Toll-like receptors (TLRs. Several other bacterial pathogens like Salmonella, Yersinia, Staphylococcus aureus but also non-pathogens express similar proteins. We discuss here the pathogenic potential of TcpC and its interaction with TLRs and TLR-adapter proteins on the molecular level and compare its activity with the activity of other bacterial TIR-containing proteins. Finally, we analyze and compare the structure of bacterial TIR-domains with the TIR-domains of TLRs and TLR-adapters.

  16. A functional variant at miR-34a binding site in toll-like receptor 4 gene alters susceptibility to hepatocellular carcinoma in a Chinese Han population.

    Jiang, Zi-Cheng; Tang, Xian-Mei; Zhao, Ying-Ren; Zheng, Lei

    2014-12-01

    Toll-like receptor 4 (TLR4) plays a key role in prompting the innate or immediate response. A growing body of evidence suggests that genetic variants of TLR4 gene were associated with the development of cancers. This study aimed to investigate the relationship of a functional variant (rs1057317) at microRNA-34a (miR-34a) binding site in toll-like receptor 4 gene and the risk of hepatocellular carcinoma. A single center-based case-control study was conducted. In this study, the polymerase chain reaction (PCR) and direct sequencing were used to genotype sequence variants of TLR4 in 426 hepatocellular carcinoma cases and 438 controls. The modification of rs1057317 on the binding of hsa-miR-34a to TLR4 messenger RNA (mRNA) was measured by luciferase activity assay. Individuals carrying the AA genotypes for the rs1057317 were associated significantly with increased risk of hepatocellular carcinoma comparing with those carrying wild-type homozygous CC genotypes (adjusted odds ratio [OR] by sex and age, from 1.116 to 2.452, P = 0.013). The activity of the reporter vector was lower in the reporter vector carrying C allele than the reporter vector carrying A allele. Furthermore, the expression of TLR4 was detected in the peripheral blood mononucleated cell of hepatocellular carcinoma (HCC) patients, suggesting that mRNA and protein levels of TLR4 might be associated with SNP rs1057317. Collectively, these results suggested that the risk of hepatocellular carcinoma was associated with a functional variant at miR-34a binding site in toll-like receptor 4 gene. miR-34a/TLR4 axis may play an important role in the development of hepatocellular carcinoma. PMID:25179842

  17. Toll-Like Receptors on Human Mesenchymal Stem Cells Drive their Migration and Immunomodulating Responses

    Tomchuck, Suzanne L.; Zwezdaryk, Kevin J.; Coffelt, Seth B.; Waterman, Ruth S.; Danka, Elizabeth S; Scandurro, Aline B.

    2007-01-01

    Adult human bone marrow-derived mesenchymal stem cells (hMSCs) are under study as therapeutic delivery agents that assist in the repair of damaged tissues. To achieve the desired clinical outcomes for this strategy requires a better understanding of the mechanisms that drive the recruitment, migration and engraftment of hMSCs to the targeted tissues. It is known that hMSCs are recruited to sites of stress or inflammation to fulfill their repair function. It is recognized that toll-like recept...

  18. Toll-Like Receptor 3 and Suppressor of Cytokine Signaling Proteins Regulate CXCR4 and CXCR7 Expression in Bone Marrow-Derived Human Multipotent Stromal Cells

    Tomchuck, Suzanne L.; Henkle, Sarah L.; Coffelt, Seth B.; Betancourt, Aline M.

    2012-01-01

    Background The use of bone marrow-derived human multipotent stromal cells (hMSC) in cell-based therapies has dramatically increased in recent years, as researchers have exploited the ability of these cells to migrate to sites of tissue injury, inflammation, and tumors. Our group established that hMSC respond to “danger” signals – by-products of damaged, infected or inflamed tissues – via activation of Toll-like receptors (TLRs). However, little is known regarding downstream signaling mediated...

  19. Contrasting patterns of polymorphism and selection in bacterial-sensing toll-like receptor 4 in two house mouse subspecies.

    Fornuskova, Alena; Bryja, Josef; Vinkler, Michal; Macholán, Miloš; Piálek, Jaroslav

    2014-07-01

    Detailed investigation of variation in genes involved in pathogen recognition is crucial for understanding co-evolutionary processes between parasites and their hosts. Triggering immediate innate response to invading microbes, Toll-like receptors (TLRs) belong presently among the best-studied receptors of vertebrate immunity. TLRs exhibit remarkable interspecific variation and also intraspecific polymorphism is well documented. In humans and laboratory mice, several studies have recently shown that single amino acid substitution may significantly alter receptor function. Unfortunately, data concerning polymorphism in free-living species are still surprisingly scarce. In this study, we analyzed the polymorphism of Toll-like receptor 4 (Tlr4) over the Palearctic range of house mouse (Mus musculus). Our results reveal contrasting evolutionary patterns between the two recently (0.5 million years ago) diverged house mouse subspecies: M. m. domesticus (Mmd) and M. m. musculus (Mmm). Comparison with cytochrome b indicates strong directional selection in Mmd Tlr4. Throughout the whole Mmd western Palaearctic region, a single variant of the ligand-binding region is spread, encoded mainly by one dominant haplotype (71% of Mmd). In contrast, Tlr4 in Mmm is much more polymorphic with several haplotypes at intermediate frequencies. Moreover, we also found clear signals of recombination between two principal haplogroups in Mmm, and we identified eight sites under positive selection in our dataset. Our results suggest that observed differences in Tlr4 diversity may be attributed to contrasting parasite-mediated selection acting in the two subspecies. PMID:25165529

  20. Characterization and functional analysis of toll-like receptor 4 in Chinese soft-shelled turtle Pelodiscus sinensis.

    Zhou, Yingshan; Liang, Quan; Li, Weifen; Gu, Yuanxing; Liao, Xun; Fang, Weihuan; Li, Xiaoliang

    2016-10-01

    Mammalian Toll-like receptor 4 (TLR4) recognizes lipopolysaccharide (LPS) in initiating the innate immune responses. Early studies indicate that turtles are more resistant to LPS challenge than mammals. It remains unknown if turtles express TLR4 and why they are more resistant to LPS. In this study, TLR4 gene from Chinese soft-shelled turtle, Pelodiscus sinensis, was cloned and characterized. The full length cDNA of turtle TLR4 (tTLR4) consists of 3396 base pairs with an 2499-bp open reading frame, encoding 833 amino acids. Phylogenetic and syntenic analyses suggest that tTLR4 is to be orthologous to human TLR4. Its mRNA expression was up-regulated in spleen and blood of turtles upon Aeromonas hydrophila infection. Stimulation of turtle peripheral blood monocytes with LPS significantly upregulated tTLR4 mRNA and inflammation-related gene expression, such as Interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2). In tTLR4-expressing HEK293 cells, higher concentration of LPS exposure could enhance the activity of the NF-κB promoter, but not the INF-β promoter. Such activity required co-expression of turtle myeloid differentiation factor 2 (tMD2) and cluster of differentiation 14 (tCD14). These results provide evidence for a functional TLR4 in reptiles and, together with the syntenic analysis, support the idea that the TLR4 receptor for LPS recognition may have arisen after reptiles. PMID:27259833

  1. Low expression of Toll-like receptors in peripheral blood mononuclear cells of pediatric patients with acute lymphoblastic leukemia.

    Sánchez-Cuaxospa, María; Contreras-Ramos, Alejandra; Pérez-Figueroa, Erandi; Medina-Sansón, Aurora; Jiménez-Hernández, Elva; Torres-Nava, José R; Rojas-Castillo, Emilio; Maldonado-Bernal, Carmen

    2016-08-01

    Cancer is the second most common cause of death among children aged 1-14 years. Leukemia accounts for one-third of all childhood cancers, 78% of which is acute lymphoblastic leukemia (ALL). The development of cancer has been associated with malignant cells that express low levels of immunogenic molecules, which facilitates their escape from the antineoplastic immune response. It is thought that it may be possible to rescue the antineoplastic immune response through the activation of recognition receptors, such as Toll-like receptors (TLRs), which activate the innate immune system. TLRs are type I membrane glycoproteins expressed mainly in immune system cells such as monocytes, neutrophils, macrophages, dendritic cells, T, B and natural killer cells. The aim of the present study was to evaluate the expression of TLR1, TLR3, TLR4, TLR7 and TLR9 in peripheral blood mononuclear cells (PBMCs) in patients with ALL and prior to any treatment. PBMCs were obtained from 50 pediatric patients diagnosed with ALL and from 20 children attending the ophthalmology and orthopedics services. The mean fluorescence intensity was obtained by analysis of immunofluorescence. We found lower expression levels of TLR1, TLR3, TLR4, TLR7 and TLR9 in PBMCs from patients with ALL compared with those from control patients. We also observed that the PBMCs from patients with Pre-B and B ALL had lower TLR4 expression than controls and patients with Pro-B, Pre-B, B and T ALL had lower TLR7 expression than controls. The present study is the first to demonstrate reduced expression of TLRs in PBMCs from pediatric patients with ALL. This finding is of great relevance and may partly explain the reduction in the antineoplastic immune response in patients with ALL. PMID:27277333

  2. Knockout of Toll-Like Receptors 2 and 4 Prevents Renal Ischemia-Reperfusion-Induced Cardiac Hypertrophy in Mice

    Trentin-Sonoda, Mayra; da Silva, Rogério Cirino; Kmit, Fernanda Vieira; Abrahão, Mariana Vieira; Monnerat Cahli, Gustavo; Brasil, Guilherme Visconde; Muzi-Filho, Humberto; Silva, Paulo André; Tovar-Moll, Fernanda Freire; Vieyra, Adalberto; Medei, Emiliano; Carneiro-Ramos, Marcela Sorelli

    2015-01-01

    We investigated whether the pathways linked to Toll-like receptors 2 and 4 (TLRs) are involved in renal ischemia-reperfusion (I/R)-induced cardiac hypertrophy. Wild type (WT) C57BL/6J, TLR2-/- and TLR4-/- mice were subjected to left kidney ischemia for 60 min followed by reperfusion for 5, 8, 12 and 15 days. Proton density magnetic resonance showed alterations in the injured kidney from WT mice, together with signs of parenchymal edema and higher levels of vimentin mRNA, accompanied by: (i) s...

  3. Selectively targeting the toll-like receptor 9 (TLR9) – IRF 7 signaling pathway by polymer blend particles

    Chen, Helen C.; Zhan, Xi; Tran, Kenny K.; Shen, Hong

    2013-01-01

    Signaling through toll-like receptor 9 (TLR9) has been exploited for cancer therapy. The stimulation of TLR9 leads to two bifurcating signaling pathways – NF-κB-dependent pro-inflammatory cytokines pathway and IRF-7-dependent type I interferons (IFNs) pathway. In this study, we employ polymer blend particles to present the synthetic ligand, CpG oligonucleotides (CpG ODNs) to TLR9. The polymer blend particles are made from the blend of pH-insensitive and pH-sensitive copolymer. By tailoring th...

  4. Comparison of Cellular Uptake and Inflammatory Response via Toll-Like Receptor 4 to Lipopolysaccharide and Titanium Dioxide Nanoparticles

    Akiyoshi Taniguchi; Koki Kanehira; Sharmy Saimon Mano

    2013-01-01

    The innate immune response is the earliest cellular response to infectious agents and mediates the interactions between microbes and cells. Toll-like receptors (TLRs) play an important role in these interactions. We have already shown that TLRs are involved with the uptake of titanium dioxide nanoparticles (TiO2 NPs) and promote inflammatory responses. In this paper, we compared role of cellular uptake and inflammatory response via TLR 4 to lipopolysaccharide (LPS) and TiO2 NPs. In the case o...

  5. Novel critical role of Toll-like receptor 4 in lung ischemia-reperfusion injury and edema

    Zanotti, Giorgio; Casiraghi, Monica; Abano, John B.; Tatreau, Jason R.; Sevala, Mayura; Berlin, Hilary; Smyth, Susan; Funkhouser, William K.; Burridge, Keith; Randell, Scott H.; Egan, Thomas M.

    2009-01-01

    Toll-like receptors (TLRs) of the innate immune system contribute to noninfectious inflammatory processes. We employed a murine model of hilar clamping (1 h) with reperfusion times between 15 min and 3 h in TLR4-sufficient (C3H/OuJ) and TLR4-deficient (C3H/HeJ) anesthetized mice with additional studies in chimeric and myeloid differentiation factor 88 (MyD88)- and TLR4-deficient mice to determine the role of TLR4 in lung ischemia-reperfusion injury. Human pulmonary microvascular endothelial m...

  6. Administration of a Toll-Like Receptor 9 Agonist Decreases the Proviral Reservoir in Virologically Suppressed HIV-Infected Patients

    Winckelmann, Anni A.; Lærke V Munk-Petersen; Thomas A. Rasmussen; Jesper Melchjorsen; Thomas J Hjelholt; David Montefiori; Lars Østergaard; Søgaard, Ole S.; Martin Tolstrup

    2013-01-01

    Toll-like receptor (TLR) agonists can reactivate HIV from latently infected cells in vitro. We aimed to investigate the TLR-9 agonist, CPG 7909's in vivo effect on the proviral HIV reservoir and HIV-specific immunity. This was a post-hoc analysis of a double-blind randomized controlled vaccine trial. HIV-infected adults were randomized 1:1 to receive pneumococcal vaccines with or without 1 mg CPG 7909 as adjuvant at 0, 3 and 9 months. In patients on suppressive antiretroviral therapy we quant...

  7. Hypoxia induced HMGB1 and mitochondrial DNA interactions mediate tumor growth in hepatocellular carcinoma through Toll Like Receptor 9

    Liu, Yao; Yan, Wei; Tohme, Samer; Chen, Man; Fu, Yu; Tian, Dean; Lotze, Michael; Tang, Daolin; Tsung, Allan

    2015-01-01

    Background and aims The mechanisms of hypoxia-induced tumor growth remain unclear. Hypoxia induces intracellular translocation and release of a variety of damage associated molecular patterns (DAMPs) such as nuclear HMGB1 and mitochondrial DNA (mtDNA). In inflammation, Toll-like receptor (TLR)-9 activation by DNA-containing immune complexes has been shown to be mediated by HMGB1. We thus hypothesize that HMGB1 binds mtDNA in the cytoplasm of hypoxic tumor cells and promotes tumor growth through activating TLR9 signaling pathways. Methods C57BL6 mice were injected with Hepa1-6 cancer cells. TLR9 and HMGB1 were inhibited using shRNA or direct antagonists. Huh7 and Hepa1-6 cancer cells were investigated in vitro to investigate how the interaction of HMGB1 and mtDNA activates TLR9 signaling pathways. Results During hypoxia, HMGB1 translocates from the nucleus to the cytosol and binds to mtDNA released from damaged mitochondria. This complex subsequently activates TLR9 signaling pathways to promote tumor cell proliferation. Loss of HMGB1 or mtDNA leads to a defect in TLR9 signaling pathways in response to hypoxia, resulting in decreased tumor cell proliferation. Also, the addition of HMGB1 and mtDNA leads to the activation of TLR-9 and subsequent tumor cell proliferation. Moreover, TLR9 is overexpressed in both hypoxic tumor cells in vitro and in human hepatocellular cancer (HCC) specimens; and, knockdown of either HMGB1 or TLR9 from HCC cells suppressed tumor growth in vivo after injection in mice. Conclusions Our data reveals a novel mechanism by which the interactions of HMGB1 and mtDNA activate TLR9 signaling during hypoxia to induce tumor growth. PMID:25681553

  8. Extracellular heat-shock protein 70 aggravates cerulein-induced pancreatitis through toll-like receptor-4 in mice

    SONG Jun-min; WANG Rong; LIU Hong-xiang; LI Yuan; ZENG Yu-jian; ZHOU Zong-guang; LIU Hai-yi; XU Bing; WANG Ling; ZHOU Bin

    2008-01-01

    Background In patients suffering from acute pancreatitis, the pathogenesis is not completely understood, and several recent studies in vitro suggested that heat shock proteins might play an important role in cell signaling. To investigate the possible role of extracellular heat shock protein 70 (Hsp70) in pancreatitis, toll-like receptor-4 (TLR4)-deficient and wild-type mice were administered with exogenous Hsp70 during the course of cerulein-induced pancreatitis (CIP).Methods Acute pancreatitis was induced by 5 intraperitoneal injections of cerulein at hourly intervals, and then treated with recombinant Hsp70 through the caudal vein 4 hours after the start of cerulein injections. Subsequently serum amylase and serum cytokines levels were detected. Histologic alteration of the pancreas was evaluated. Tumor necrosis factor alpha (TNF-a) concentrations and myeloperoxidase (MPO) activity in both pancreas and lungs were analyzed. The nuclear factor kappa B (NF-KB) activation in pancreatic tissue was measured using a sensitive RelA enzyme-linked immunosorbent assay.Results Treatment with recombinant Hsp70 to wild-type mice in CIP resulted in significant aggravation of inflammation in pancreas, elevated levels of serum cytokines, up-regulation of pulmonary MPO activity and increase of lung tissues TNF-α concentrations. In contrast, treatment with Hsp70 to TLR4-deficient mice had little effect on serum cytokines levels, pancreatic inflammation, pulmonary MPO activity and TNF-a concentrations.Conclusions The results suggest that extracellular HspTO might induce systemic inflammatory response syndrome (SIRS)-Iike response in vivo and TLR4 might be involved in the Hsp70-mediated activation of inflammatory reaction in the progression of CIP without infection.

  9. Origin and consequences of brain Toll-like receptor 4 pathway stimulation in an experimental model of depression

    Madrigal José LM

    2011-11-01

    Full Text Available Abstract Background There is a pressing need to identify novel pathophysiological pathways relevant to depression that can help to reveal targets for the development of new medications. Toll-like receptor 4 (TLR-4 has a regulatory role in the brain's response to stress. Psychological stress may compromise the intestinal barrier, and increased gastrointestinal permeability with translocation of lipopolysaccharide (LPS from Gram-negative bacteria may play a role in the pathophysiology of major depression. Methods Adult male Sprague-Dawley rats were subjected to chronic mild stress (CMS or CMS+intestinal antibiotic decontamination (CMS+ATB protocols. Levels of components of the TLR-4 signaling pathway, of LPS and of different inflammatory, oxidative/nitrosative and anti-inflammatory mediators were measured by RT-PCR, western blot and/or ELISA in brain prefrontal cortex. Behavioral despair was studied using Porsolt's test. Results CMS increased levels of TLR-4 and its co-receptor MD-2 in brain as well as LPS and LPS-binding protein in plasma. In addition, CMS also increased interleukin (IL-1β, COX-2, PGE2 and lipid peroxidation levels and reduced levels of the anti-inflammatory prostaglandin 15d-PGJ2 in brain tissue. Intestinal decontamination reduced brain levels of the pro-inflammatory parameters and increased 15d-PGJ2, however this did not affect depressive-like behavior induced by CMS. Conclusions Our results suggest that LPS from bacterial translocation is responsible, at least in part, for the TLR-4 activation found in brain after CMS, which leads to release of inflammatory mediators in the CNS. The use of Gram-negative antibiotics offers a potential therapeutic approach for the adjuvant treatment of depression.

  10. Curcumin Modulates Macrophage Polarization Through the Inhibition of the Toll-Like Receptor 4 Expression and its Signaling Pathways

    Yaoyao Zhou

    2015-05-01

    Full Text Available Background: Curcumin, the active ingredient in curcuma rhizomes, has a wide range of therapeutic effects. However, its atheroprotective activity in human acute monocytic leukemia THP-1 cells remains unclear. We investigated the activity and molecular mechanism of action of curcumin in polarized macrophages. Methods: Phorbol myristate acetate (PMA-treated THP-1 cells were differentiated to macrophages, which were further polarized to M1 cells by lipopolysaccharide (LPS; 1 µg/ml and interferon (IFN-γ (20 ng/ml and treated with varying curcumin concentrations. [3H]thymidine (3H-TdR incorporation assays were utilized to measure curcumin-induced growth inhibition. The expression of tumor necrosis factor-a (TNF-a, interleukin (IL-6, and IL-12B (p40 were measured by quantitative real-time polymerase chain reaction (PCR and enzyme-linked immunosorbent assay (ELISA. Macrophage polarization and its mechanism were evaluated by flow cytometry and western blot. Additionally, toll-like receptor 4 (TLR4 small interfering RNA and mitogen-activated protein kinase (MAPK inhibitors were used to further confirm the molecular mechanism of curcumin on macrophage polarization. Results: Curcumin dose-dependently inhibited M1 macrophage polarization and the production of TNF-a, IL-6, and IL-12B (p40. It also decreased TLR4 expression, which regulates M1 macrophage polarization. Furthermore, curcumin significantly inhibited the phosphorylation of ERK, JNK, p38, and nuclear factor (NF-γB. In contrast, SiTLR4 in combination with p-JNK, p-ERK, and p-p38 inhibition reduced the effect of curcumin on polarization. Conclusions: Curcumin can modulate macrophage polarization through TLR4-mediated signaling pathway inhibition, indicating that its effect on macrophage polarization is related to its anti-inflammatory and atheroprotective effects. Our data suggest that curcumin could be used as a therapeutic agent in atherosclerosis.

  11. Gut flora, Toll-like receptors and nuclear receptors: a tripartite communication that tunes innate immunity in large intestine.

    Lundin, Annelie; Bok, Chek Mei; Aronsson, Linda; Björkholm, Britta; Gustafsson, Jan-Ake; Pott, Sebastian; Arulampalam, Velmurugesan; Hibberd, Martin; Rafter, Joseph; Pettersson, Sven

    2008-05-01

    Separating the large intestine from gut flora is a robust layer of epithelial cells. This barrier is armed with an array of recognizing receptors that collectively set the host innate response. Here, we use nuclear receptors (NRs) and Toll-like receptors (TLRs), suggested to act as second messengers in the communication between microorganisms and epithelial cells, as probes to assess the impact of gut flora on innate immunity in germ-free (GF) mice. Using quantitative real-time polymerase chain reaction analyses, we show that 37/49 NRs are expressed in colonic cells of GF mice. Of these, 5 can be modulated by resident flora: LXRalpha, RORgamma and CAR show reduced expression and Nur77 and GCNF display elevated expression in conventionally raised mice compared with GF. Moreover, increased expression levels of TLR-2 and TLR-5 are observed in specific pathogen-free (SPF) mice compared with GF mice, and CAR expression is connected to the TLR-2 signalling pathway. Infections of GF or SPF mice with Yersinia pseudotuberculosis, show that GF intestinal epithelial cells fail to respond, except for CAR, which is downregulated. In contrast, SPF epithelial cells show a downregulation of all the NRs except CAR, which appears to be unaffected. Our findings indicate that gut flora contributes to the development of an intact barrier function. PMID:18088401

  12. Autoinmunidad y receptores tipo Toll = Autoimmunity and toll-like receptors

    Ossa Giraldo, Ana Claudia

    2012-07-01

    Full Text Available La respuesta inmune innata está conformada por un conjunto de mecanismos que permiten reconocer los componentes propios del organismo y diferenciarlos de los microorganismos invasores para generar una primera línea de defensa. Este reconocimiento está mediado por diferentes receptores presentes en la superficie y en el interior de células inmunes y no inmunes; entre ellos se encuentran los siguientes: receptores tipo Toll (RTT, receptores de lectinas tipo C, receptores tipo GIR (genes inducibles por ácido retinoico y receptores tipo Nod y NALP, que reconocen patrones moleculares asociados a microorganismos (PMAM. Gracias a esta capacidad de discriminación, adquirida evolutivamente por la inmunidad innata, se ha aceptado tradicionalmente que los procesos autoinmunes no están relacionados con esta sino con la inmunidad adquirida. Sin embargo, varios estudios han demostrado que esa teoría no es totalmente cierta y que algunos mecanismos efectores de la inmunidad innata participan en la generación de las enfermedades autoinmunes o en la potenciación de su fisiopatología. En esta revisión se estudia la contribución de la inmunidad innata a la autoinmunidad con énfasis en el papel de los receptores tipo Toll.

  13. High glucose induces inflammatory cytokine through protein kinase C-induced toll-like receptor 2 pathway in gingival fibroblasts

    Jiang, Shao-Yun, E-mail: jiangshaoyun@yahoo.com [School of Dentistry, Tianjin Medical University, 12 Qi Xiang Tai Street, Heping District, Tianjin 300070 (China); Wei, Cong-Cong; Shang, Ting-Ting; Lian, Qi; Wu, Chen-Xuan [School of Dentistry, Tianjin Medical University, 12 Qi Xiang Tai Street, Heping District, Tianjin 300070 (China); Deng, Jia-Yin, E-mail: yazhou2991@126.com [School of Dentistry, Tianjin Medical University, 12 Qi Xiang Tai Street, Heping District, Tianjin 300070 (China)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer High glucose significantly induced TLR2 expression in gingival fibroblasts. Black-Right-Pointing-Pointer High glucose increased NF-{kappa}B p65 nuclear activity, IL-1{beta} and TNF-{alpha} levels. Black-Right-Pointing-Pointer PKC-{alpha}/{delta}-TLR2 pathway is involved in periodontal inflammation under high glucose. -- Abstract: Toll-like receptors (TLRs) play a key role in innate immune response and inflammation, especially in periodontitis. Meanwhile, hyperglycemia can induce inflammation in diabetes complications. However, the activity of TLRs in periodontitis complicated with hyperglycemia is still unclear. In the present study, high glucose (25 mmol/l) significantly induced TLR2 expression in gingival fibroblasts (p < 0.05). Also, high glucose increased nuclear factor kappa B (NF-{kappa}B) p65 nuclear activity, tumor necrosis factor-{alpha} (TNF-{alpha}) and interleukin-l{beta} (IL-1{beta}) levels. Protein kinase C (PKC)-{alpha} and {delta} knockdown with siRNA significantly decreased TLR2 and NF-{kappa}B p65 expression (p < 0.05), whereas inhibition of PKC-{beta} had no effect on TLR2 and NF-{kappa}B p65 under high glucose (p < 0.05). Additional studies revealed that TLR2 knockdown significantly abrogated high-glucose-induced NF-{kappa}B expression and inflammatory cytokine secretion. Collectively, these data suggest that high glucose stimulates TNF-{alpha} and IL-1{beta} secretion via inducing TLR2 through PKC-{alpha} and PKC-{delta} in human gingival fibroblasts.

  14. Baicalin inhibits toll-like receptor 2/4 expression and downstream signaling in rat experimental periodontitis.

    Sun, Jun-Yi; Li, Dong-Ling; Dong, Yan; Zhu, Chun-Hui; Liu, Jin; Li, Jue-Dan; Zhou, Tao; Gou, Jian-Zhong; Li, Ang; Zang, Wei-Jin

    2016-07-01

    Periodontitis is a severe inflammatory response, leading to characteristic periodontal soft tissue destruction and alveolar bone resorption. Baicalin possesses potent anti-inflammatory activity; however, it is still unclear whether baicalin regulates toll-like receptor (TLR) 2/4 expression and downstream signaling during the process of periodontitis. In this study, the cervical area of the maxillary second molars of rats was ligated and inoculated with Porphyromonas gingivalis (P. gingivalis) for 4weeks to induce periodontitis. Some rats with periodontitis were treated intragastrically with baicalin (50, 100 or 200mg/kg/day) or vehicle for 4weeks. Compared with the sham group, the levels of TLR2, TLR4 and MyD88 expression and the p38 MAPK and NF-κB activation were up-regulated in the experimental periodontitis group (EPG), accompanied by marked alveolar bone loss and severe inflammation. Treatment with 100 or 200mg/kg/day baicalin dramatically reduced the alveolar bone loss, the levels of HMGB1, TNF-α, IL-1β, and MPO expression, and the numbers of inflammatory infiltrates in the gingival tissues. Importantly, treatment with 100 or 200mg/kg/day baicalin mitigated the periodontitis-up-regulated TLR2, TLR4 and MyD88 expression, and the p38 MAPK and NF-κB activation. Hence, the blockage of the TLR2 and TLR4/MyD88/p38 MAPK/NF-κB signaling by baicalin may contribute to its anti-inflammatory effects in rat model of periodontitis. In conclusion, these novel findings indicate that baicalin inhibits the TLR2 and TLR4 expression and the downstream signaling and mitigates inflammatory responses and the alveolar bone loss in rat experimental periodontitis. Therefore, baicalin may be a potential therapeutic agent for treatment of periodontitis. PMID:27107801

  15. Intra-Peritoneal Administration of Mitochondrial DNA Provokes Acute Lung Injury and Systemic Inflammation via Toll-Like Receptor 9.

    Zhang, Lemeng; Deng, Songyun; Zhao, Shuangping; Ai, Yuhang; Zhang, Lina; Pan, Pinhua; Su, Xiaoli; Tan, Hongyi; Wu, Dongdong

    2016-01-01

    The pathogenesis of sepsis is complex. Mitochondrial dysfunction, which is responsible for energy metabolism, intrinsic apoptotic pathway, oxidative stress, and systemic inflammatory responses, is closely related with severe sepsis induced death. Mitochondria DNA (mtDNA) contain un-methylated cytosine phosphate guanine (CpG) motifs, which exhibit immune stimulatory capacities. The aim of this study was to investigate the role and mechanism of mtDNA release on lipopolysaccharide (LPS) induced acute lung injury (ALI) and systemic inflammation. Following LPS injection, plasma mtDNA copies peak at 8 h. Compared with wild-type (WT) mice, mtDNA in toll like receptor 4 knockout (TLR4 KO) mice were significantly decreased. MtDNA intra-peritoneal administration causes apparent ALI as demonstrated by increased lung injury score, bronchoalveolar lavage fluid (BALF) total protein and wet/dry (W/D) ratio; mtDNA injection also directly provokes systemic inflammation, as demonstrated by increased IL-1β, IL-6, high-mobility group protein B1 (HMGB1) level; while nuclear DNA (nDNA) could not induce apparent ALI and systemic inflammation. However, compared with WT mice, TLR4 KO could not protect from mtDNA induced ALI and systemic inflammation. Specific TLR9 inhibitor, ODN 2088 pretreatment can significantly attenuate mtDNA induced ALI and systemic inflammation, as demonstrated by improved lung injury score, decreased lung wet/dry ratio, BALF total protein concentration, and decreased systemic level of IL-1β, IL-6 and HMGB1. MtDNA administration activates the expression of p-P38 mitogen-activated protein kinases (MAPK) in lung tissue and specific TLR9 inhibitor pretreatment can attenuate this activation. Thus, LPS-induced mtDNA release occurs in a TLR4-dependent manner, and mtDNA causes acute lung injury and systemic inflammation in a TLR9-dependent and TLR4-independent manner. PMID:27589725

  16. A flagellin-derived toll-like receptor 5 agonist stimulates cytotoxic lymphocyte-mediated tumor immunity.

    Nicholas D Leigh

    Full Text Available Toll-like receptor (TLR mediated recognition of pathogen associated molecular patterns allows the immune system to rapidly respond to a pathogenic insult. The "danger context" elicited by TLR agonists allows an initially non-immunogenic antigen to become immunogenic. This ability to alter environment is highly relevant in tumor immunity, since it is inherently difficult for the immune system to recognize host-derived tumors as immunogenic. However, immune cells may have encountered certain TLR ligands associated with tumor development, yet the endogenous stimulation is typically not sufficient to induce spontaneous tumor rejection. Of special interest are TLR5 agonists, because there are no endogenous ligands that bind TLR5. CBLB502 is a pharmacologically optimized TLR5 agonist derived from Salmonella enterica flagellin. We examined the effect of CBLB502 on tumor immunity using two syngeneic lymphoma models, both of which do not express TLR5, and thus do not directly respond to CBLB502. Upon challenge with the T-cell lymphoma RMAS, CBLB502 treatment after tumor inoculation protects C57BL/6 mice from death caused by tumor growth. This protective effect is both natural killer (NK cell- and perforin-dependent. In addition, CBLB502 stimulates clearance of the B-cell lymphoma A20 in BALB/c mice in a CD8(+ T cell-dependent fashion. Analysis on the cellular level via ImageStream flow cytometry reveals that CD11b(+ and CD11c(+ cells, but neither NK nor T cells, directly respond to CBLB502 as determined by NFκB nuclear translocation. Our findings demonstrate that CBLB502 stimulates a robust antitumor response by directly activating TLR5-expressing accessory immune cells, which in turn activate cytotoxic lymphocytes.

  17. Effect of baicalin on toll-like receptor 4-mediated ischemia/reperfusion inflammatory responses in alcoholic fatty liver condition

    Alcoholic fatty liver is susceptible to secondary stresses such as ischemia/reperfusion (I/R). Baicalin is an active component extracted from Scutellaria baicalensis, which is widely used in herbal preparations for treatment of hepatic diseases and inflammatory disorders. This study evaluated the potential beneficial effect of baicalin on I/R injury in alcoholic fatty liver. Rats were fed an alcohol liquid diet or a control isocaloric diet for 5 weeks, and then subjected to 60 min of hepatic ischemia and 5 h of reperfusion. Baicalin (200 mg/kg) was intraperitoneally administered 24 and 1 h before ischemia. After reperfusion, baicalin attenuated the increases in serum alanine aminotransferase activity, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels in alcoholic fatty liver. The increased levels of TNF-α and IL-6 mRNA expression and inducible nitric oxide synthase and cyclooxygenase-2 protein and mRNA expressions increased after reperfusion, which were higher in ethanol-fed animals, were attenuated by baicalin. In ethanol-fed animals, baicalin attenuated the increases in toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 protein expressions and the nuclear translocation of NF-κB after reperfusion. In conclusion, our findings suggest that baicalin ameliorates I/R-induced hepatocellular damage by suppressing TLR4-mediated inflammatory responses in alcoholic fatty liver. -- Highlights: ► Baicalin attenuates hepatic I/R-induced inflammation in alcoholic fatty liver. ► Baicalin downregulates TLR4, MyD88 expression during I/R in alcoholic fatty liver. ► Baicalin attenuates NF-κB nuclear translocation during I/R in alcoholic fatty liver.

  18. Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo

    Schaap, Marianne C. L.; Hou, Baidong; van der Poll, Tom; Nieuwland, Rienk; van ‘t Veer, Cornelis

    2016-01-01

    Streptococcus (S.) pneumoniae strains vary considerably in their ability to cause invasive disease in humans, which is at least in part determined by the capsular serotype. Platelets have been implicated as sentinel cells in the circulation for host defence. One of their utensils for this function is the expression of Toll-like receptors (TLRs). We here aimed to investigate platelet response to S. pneumoniae and a role for TLRs herein. Platelets were stimulated using four serotypes of S. pneumonia including an unencapsulated mutant strain. In vitro aggregation and flow cytometry assays were performed using blood of healthy volunteers, or blood of TLR knock out and WT mice. For in vivo pneumonia experiments, platelet specific Myd88 knockout (Plt-Myd88-/-) mice were used. We found that platelet aggregation was induced by unencapsulated S. pneumoniae only. Whole blood incubation with all S. pneumoniae serotypes tested resulted in platelet degranulation and platelet-leukocyte complex formation. Platelet activation was TLR independent, as responses were not inhibited by TLR blocking antibodies, not induced by TLR agonists and were equally induced in wild-type and Tlr2-/-, Tlr4-/-, Tlr2/4-/-, Tlr9-/- and Myd88-/- blood. Plt-Myd88-/- and control mice displayed no differences in bacterial clearance or immune response to pneumonia by unencapsulated S. pneumoniae. In conclusion, S. pneumoniae activates platelets through a TLR-independent mechanism that is impeded by the bacterial capsule. Additionally, platelet MyD88-dependent TLR signalling is not involved in host defence to unencapsulated S. pneumoniae in vivo. PMID:27253707

  19. Immunomodulatory Effect of Toll-Like Receptor-3 Ligand Poly I:C on Cortical Spreading Depression.

    Ghaemi, Amir; Sajadian, Azadeh; Khodaie, Babak; Lotfinia, Ahmad Ali; Lotfinia, Mahmoud; Aghabarari, Afsaneh; Khaleghi Ghadiri, Maryam; Meuth, Sven; Gorji, Ali

    2016-01-01

    The release of inflammatory mediators following cortical spreading depression (CSD) is suggested to play a role in pathophysiology of CSD-related neurological disorders. Toll-like receptors (TLR) are master regulators of innate immune function and involved in the activation of inflammatory responses in the brain. TLR3 agonist poly I:C exerts anti-inflammatory effect and prevents cell injury in the brain. The aim of the present study was to examine the effect of systemic administration of poly I:C on the release of cytokines (TNF-α, IFN-γ, IL-4, TGF-β1, and GM-CSF) in the brain and spleen, splenic lymphocyte proliferation, expression of GAD65, GABAAα, GABAAβ as well as Hsp70, and production of dark neurons after induction of repetitive CSD in juvenile rats. Poly I:C significantly attenuated CSD-induced production of TNF-α and IFN-γ in the brain as well as TNF-α and IL-4 in the spleen. Poly I:C did not affect enhancement of splenic lymphocyte proliferation after CSD. Administration of poly I:C increased expression of GABAAα, GABAAβ as well as Hsp70 and decreased expression of GAD65 in the entorhinal cortex compared to CSD-treated tissues. In addition, poly I:C significantly prevented production of CSD-induced dark neurons. The data indicate neuroprotective and anti-inflammatory effects of TLR3 activation on CSD-induced neuroinflammation. Targeting TLR3 may provide a novel strategy for developing new treatments for CSD-related neurological disorders. PMID:25416860

  20. Human decidual macrophages and NK cells differentially express Toll-like receptors and display distinct cytokine profiles upon TLR stimulation.

    Duriez, Marion; Quillay, Héloïse; Madec, Yoann; El Costa, Hicham; Cannou, Claude; Marlin, Romain; de Truchis, Claire; Rahmati, Mona; Barré-Sinoussi, Françoise; Nugeyre, Marie-Thérèse; Menu, Elisabeth

    2014-01-01

    Maternofetal pathogen transmission is partially controlled at the level of the maternal uterine mucosa at the fetal implantation site (the decidua basalis), where maternal and fetal cells are in close contact. Toll-like receptors (TLRs) may play an important role in initiating rapid immune responses against pathogens in the decidua basalis, however the tolerant microenvironment should be preserved in order to allow fetal development. Here we investigated the expression and functionality of TLRs expressed by decidual macrophages (dMs) and NK cells (dNKs), the major decidual immune cell populations. We report for the first time that both human dMs and dNK cells express mRNAs encoding TLRs 1-9, albeit with a higher expression level in dMs. TLR2, TLR3, and TLR4 protein expression checked by flow cytometry was positive for both dMs and dNK cells. In vitro treatment of primary dMs and dNK cells with specific TLR2, TLR3, TLR4, TLR7/8, and TLR9 agonists enhanced their secretion of pro- and anti-inflammatory cytokines, as well as cytokines and chemokines involved in immune cell crosstalk. Only dNK cells released IFN-γ, whereas only dMs released IL-1β, IL-10, and IL-12. TLR9 activation of dMs resulted in a distinct pattern of cytokine expression compared to the other TLRs. The cytokine profiles expressed by dMs and dNK cells upon TLR activation are compatible with maintenance of the fetotolerant immune environment during initiation of immune responses to pathogens at the maternofetal interface. PMID:25071732

  1. Toll-Like Receptor (TLR) and Nucleosome-binding Oligomerization Domain (NOD) gene polymorphisms and endometrial cancer risk

    Endometrial cancer is the most common gynaecological malignancy in women of developed countries. Many risk factors implicated in endometrial cancer trigger inflammatory events; therefore, alterations in immune response may predispose an individual to disease. Toll-like receptors (TLRs) and nucleosome-binding oligomerization domain (NOD) genes are integral to the recognition of pathogens and are highly polymorphic. For these reasons, the aim of the study was to assess the frequency of polymorphic variants in TLR and NOD genes in an Australian endometrial cancer population. Ten polymorphisms were genotyped in 191 endometrial cancer cases and 291 controls using real-time PCR: NOD1 (rs2075822, rs2907749, rs2907748), NOD2 (rs5743260, rs2066844, rs2066845), TLR2 (rs5743708), TLR4 (rs4986790) and TLR9 (rs5743836, rs187084). Haplotype analysis revealed that the combination of the variant alleles of the two TLR9 polymorphisms, rs5743836 and rs187084, were protective for endometrial cancer risk: OR 0.11, 95% CI (0.03-0.44), p = 0.002. This result remained highly significant after adjustment for endometrial cancer risk factors and Bonferroni correction for multiple testing. There were no other associations observed for the other polymorphisms in TLR2, TLR4, NOD1 and NOD2. The variant 'C' allele of rs5743836 causes greater TLR9 transcriptional activity compared to the 'T' allele, therefore, higher TLR9 activity may be related to efficient removal of microbial pathogens within the endometrium. Clearly, the association of these TLR9 polymorphisms and endometrial cancer risk must be further examined in an independent population. The results point towards the importance of examining immune response in endometrial tumourigenesis to understand new pathways that may be implicated in disease

  2. Differential induction of the toll-like receptor 4-MyD88-dependent and -independent signaling pathways by endotoxins.

    Zughaier, Susu M; Zimmer, Shanta M; Datta, Anup; Carlson, Russell W; Stephens, David S

    2005-05-01

    The biological response to endotoxin mediated through the Toll-like receptor 4 (TLR4)-MD-2 receptor complex is directly related to lipid A structure or configuration. Endotoxin structure may also influence activation of the MyD88-dependent and -independent signaling pathways of TLR4. To address this possibility, human macrophage-like cell lines (THP-1, U937, and MM6) or murine macrophage RAW 264.7 cells were stimulated with picomolar concentrations of highly purified endotoxins. Harvested supernatants from previously stimulated cells were also used to stimulate RAW 264.7 or 23ScCr (TLR4-deficient) macrophages (i.e., indirect induction). Neisseria meningitidis lipooligosaccharide (LOS) was a potent direct inducer of the MyD88-dependent pathway molecules tumor necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 3alpha (MIP-3alpha), and the MyD88-independent molecules beta interferon (IFN-beta), nitric oxide, and IFN-gamma-inducible protein 10 (IP-10). Escherichia coli 55:B5 and Vibrio cholerae lipopolysaccharides (LPSs) at the same pmole/ml lipid A concentrations induced comparable levels of TNF-alpha, IL-1beta, and MIP-3alpha, but significantly less IFN-beta, nitric oxide, and IP-10. In contrast, LPS from Salmonella enterica serovars Minnesota and Typhimurium induced amounts of IFN-beta, nitric oxide, and IP-10 similar to meningococcal LOS but much less TNF-alpha and MIP-3alpha in time course and dose-response experiments. No MyD88-dependent or -independent response to endotoxin was seen in TLR4-deficient cell lines (C3H/HeJ and 23ScCr) and response was restored in TLR4-MD-2-transfected human embryonic kidney 293 cells. Blocking the MyD88-dependent pathway by DNMyD88 resulted in significant reduction of TNF-alpha release but did not influence nitric oxide release. IFN-beta polyclonal antibody and IFN-alpha/beta receptor 1 antibody significantly reduced nitric oxide release. N

  3. Dysfunction in macrophage toll-like receptor signaling caused by an inborn error of cationic amino acid transport.

    Kurko, Johanna; Vähä-Mäkilä, Mari; Tringham, Maaria; Tanner, Laura; Paavanen-Huhtala, Sari; Saarinen, Maiju; Näntö-Salonen, Kirsti; Simell, Olli; Niinikoski, Harri; Mykkänen, Juha

    2015-10-01

    Amino acids, especially arginine, are vital for the well-being and activity of immune cells, and disruption of amino acid balance may weaken immunity and predispose to infectious and autoimmune diseases. We present here a model of an inborn aminoaciduria, lysinuric protein intolerance (LPI), in which a single mutation in y(+)LAT1 cationic amino acid transporter gene SLC7A7 leads to a multisystem disease characterized by immunological complications, life-threatening pulmonary alveolar proteinosis and nephropathy. Macrophages are suggested to play a central role in LPI in the development of these severe secondary symptoms. We thus studied the effect of the Finnish y(+)LAT1 mutation on monocyte-derived macrophages where toll-like receptors (TLRs) act as the key molecules in innate immune response against external pathogens. The function of LPI patient and control macrophage TLR signaling was examined by stimulating the TLR2/1, TLR4 and TLR9 pathways with their associated pathogen-associated molecular patterns. Downregulation in expression of TLR9, IRF7, IRF3 and IFNB1 and in secretion of IFN-α was detected, suggesting an impaired response to TLR9 stimulation. In addition, secretion of TNF-α, IL-12 and IL-1RA by TLR2/1 stimulation and IL-12 and IL-1RA by TLR4 stimulation was increased in the LPI patients. LPI macrophages secreted significantly less nitric oxide than control macrophages, whereas plasma concentrations of inflammatory chemokines CXCL8, CXCL9 and CXCL10 were elevated in the LPI patients. In conclusion, our results strengthen the relevance of macrophages in the pathogenesis of LPI and, furthermore, suggest that cationic amino acid transport plays an important role in the regulation of innate immune responses. PMID:26210182

  4. Divergent impact of Toll-like receptor 2 deficiency on repair mechanisms in healthy muscle versus Duchenne muscular dystrophy.

    Mojumdar, Kamalika; Giordano, Christian; Lemaire, Christian; Liang, Feng; Divangahi, Maziar; Qureshi, Salman T; Petrof, Basil J

    2016-05-01

    Injury to skeletal muscle, whether acute or chronic, triggers macrophage-mediated innate immunity in a manner which can be either beneficial or harmful for subsequent repair. Endogenous ligands for Toll-like receptor 2 (TLR2) are released by damaged tissues and might play an important role in activating the innate immune system following muscle injury. To test this hypothesis, we compared macrophage behaviour and muscle repair mechanisms in mice lacking TLR2 under conditions of either acute (cardiotoxin-induced) or chronic (mdx mouse genetic model of Duchenne muscular dystrophy; DMD) muscle damage. In previously healthy muscle subjected to acute damage, TLR2 deficiency reduced macrophage numbers in the muscle post-injury but did not alter the expression pattern of the prototypical macrophage polarization markers iNOS and CD206. In addition, there was abnormal persistence of necrotic fibres and impaired regeneration in TLR2-/- muscles after acute injury. In contrast, TLR2 ablation in chronically diseased muscles of mdx mice not only resulted in significantly reduced macrophage numbers but additionally modified their phenotype by shifting from inflammatory (iNOS(pos) CD206(neg) ) to more anti-inflammatory (iNOS(neg) CD206(pos) ) characteristics. This decrease in macrophage-mediated inflammation was associated with ameliorated muscle histopathology and improved force-generating capacity of the dystrophic muscle. Our results suggest that the role of TLR2 in macrophage function and skeletal muscle repair depends greatly upon the muscle injury context, and raise the possibility that inhibition of TLR2 could serve as a useful therapeutic measure in DMD. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:26800321

  5. Toll-like receptor 2 -196 to -174 del polymorphism influences the susceptibility of Han Chinese people to Alzheimer's disease

    Mao Cai-Xia

    2011-10-01

    Full Text Available Abstract Background Toll-like receptor 2 (TLR2 represents a reasonable functional and positional candidate gene for Alzheimer's disease (AD as it is located under the linkage region of AD on chromosome 4q, and functionally is involved in the microglia-mediated inflammatory response and amyloid-β clearance. The -196 to -174 del polymorphism affects the TLR2 gene and alters its promoter activity. Methods We recruited 800 unrelated Northern Han Chinese individuals comprising 400 late-onset AD (LOAD patients and 400 healthy controls matched for gender and age. The -196 to -174 del polymorphism in the TLR2 gene was genotyped using the polymerase chain reaction (PCR method. Results There were significant differences in genotype (P = 0.026 and allele (P = 0.009 frequencies of the -196 to -174 del polymorphism between LOAD patients and controls. The del allele was associated with an increased risk of LOAD (OR = 1.31, 95% CI = 1.07-1.60, Power = 84.9%. When these data were stratified by apolipoprotein E (ApoE ε4 status, the observed association was confined to ApoE ε4 non-carriers. Logistic regression analysis suggested an association of LOAD with the polymorphism in a recessive model (OR = 1.64, 95% CI = 1.13-2.39, Bonferroni corrected P = 0.03. Conclusions Our data suggest that the -196 to -174 del/del genotype of TLR2 may increase risk of LOAD in a Northern Han Chinese population.

  6. Decreased Toll-like receptor 8 expression and lower TNF-alpha synthesis in infants with acute RSV infection

    Gagro Alenka

    2010-10-01

    Full Text Available Abstract Background Toll-like receptors (TLRs are part of the innate immune system, able to recognize pathogen-associated molecular patterns and activate immune system upon pathogen challenge. Respiratory syncytial virus (RSV is a RNA virus particularly detrimental in infancy. It could cause severe lower respiratory tract disease and recurrent infections related to inadequate development of anti-viral immunity. The reason could be inadequate multiple TLRs engagement, including TLR8 in recognition of single-stranded viral RNA and diminished synthesis of inflammatory mediators due to a lower expression. Methods Intracellular TLR8 expression in peripheral blood monocytes from RSV-infected infants was profiled and compared to healthy adults and age matched controls. Whether the observed difference in TLR8 expression is a transitory effect, infants in convalescent phase (4-6 weeks later were retested. Specific TLR8-mediated TNF-α production in monocytes during an acute and convalescent phase was analyzed. Results RSV-infected and healthy infants had lower percentage of TLR8-expressing monocytes than healthy adults whereas decreased of TLR8 protein levels were detected only for RSV-infected infant group. Lower protein levels of TLR8 in monocytes from RSV-infected infants, compared to healthy infants, negatively correlated with respiratory frequency and resulted in lower TNF-α synthesis upon a specific TLR8 stimulation. In the convalescent phase, levels of TLR8 increased, accompanied by increased TNF-α synthesis compared to acute infection. Conclusions Lower TLR8 expression observed in monocytes, during an acute RSV infection, might have a dampening impact on early anti-viral cytokine production necessary to control RSV replication, and subsequently initiate an adaptive Th1 type immune response leading to severe disease in infected infants.

  7. Toll-like receptor 4 is involved in the cell cycle modulation and required for effective human cytomegalovirus infection in THP-1 macrophages

    Arcangeletti, Maria-Cristina, E-mail: mariacristina.arcangeletti@unipr.it [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Germini, Diego; Rodighiero, Isabella [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Mirandola, Prisco [Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma (Italy); De Conto, Flora; Medici, Maria-Cristina [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Gatti, Rita [Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma (Italy); Chezzi, Carlo; Calderaro, Adriana [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy)

    2013-05-25

    Suitable host cell metabolic conditions are fundamental for the effective development of the human cytomegalovirus (HCMV) lytic cycle. Indeed, several studies have demonstrated the ability of this virus to interfere with cell cycle regulation, mainly by blocking proliferating cells in G1 or G1/S. In the present study, we demonstrate that HCMV deregulates the cell cycle of THP-1 macrophages (a cell line irreversibly arrested in G0) by pushing them into S and G2 phases. Moreover, we show that HCMV infection of THP-1 macrophages leads to Toll-like receptor 4 (TLR4) activation. Since various studies have indicated TLR4 to be involved in promoting cell proliferation, here we investigate the possible role of TLR4 in the observed HCMV-induced cell cycle perturbation. Our data strongly support TLR4 as a mediator of HCMV-triggered cell cycle activation in THP-1 macrophages favouring, in turn, the development of an efficient viral lytic cycle. - Highlights: ► We studied HCMV infection impact on THP-1 macrophage cell cycle. ► We analysed the role played by Toll-like receptor (TLR) 4 upon HCMV infection. ► HCMV pushes THP-1 macrophages (i.e. resting cells) to re-enter the cell cycle. ► TLR4 pathway inhibition strongly affects the effectiveness of HCMV replication. ► TLR4 pathway inhibition significantly decreases HCMV-induced cell cycle re-entry.

  8. Toll-like receptor 4 is involved in the cell cycle modulation and required for effective human cytomegalovirus infection in THP-1 macrophages

    Suitable host cell metabolic conditions are fundamental for the effective development of the human cytomegalovirus (HCMV) lytic cycle. Indeed, several studies have demonstrated the ability of this virus to interfere with cell cycle regulation, mainly by blocking proliferating cells in G1 or G1/S. In the present study, we demonstrate that HCMV deregulates the cell cycle of THP-1 macrophages (a cell line irreversibly arrested in G0) by pushing them into S and G2 phases. Moreover, we show that HCMV infection of THP-1 macrophages leads to Toll-like receptor 4 (TLR4) activation. Since various studies have indicated TLR4 to be involved in promoting cell proliferation, here we investigate the possible role of TLR4 in the observed HCMV-induced cell cycle perturbation. Our data strongly support TLR4 as a mediator of HCMV-triggered cell cycle activation in THP-1 macrophages favouring, in turn, the development of an efficient viral lytic cycle. - Highlights: ► We studied HCMV infection impact on THP-1 macrophage cell cycle. ► We analysed the role played by Toll-like receptor (TLR) 4 upon HCMV infection. ► HCMV pushes THP-1 macrophages (i.e. resting cells) to re-enter the cell cycle. ► TLR4 pathway inhibition strongly affects the effectiveness of HCMV replication. ► TLR4 pathway inhibition significantly decreases HCMV-induced cell cycle re-entry

  9. Enhanced antibody responses to a detoxified lipopolysaccharide-group B meningococcal outer membrane protein vaccine are due to synergistic engagement of Toll-like receptors.

    Chen, Wilbur H; Basu, Subhendu; Bhattacharjee, Apurba K; Cross, Alan S

    2010-10-01

    When given passively or elicited actively, antibodies induced by a detoxified Escherichia coli Rc chemotype (J5) mutant lipopolysaccharide (J5dLPS)-group B meningococcal outer membrane protein (OMP) complex vaccine protected animals from lethal sepsis. The protection from sepsis is believed to be dependent on high levels of antibodies against the core glycolipid (CGL), a region of LPS that is rather conserved among Enterobacteriaceae. The addition of unmethylated deoxycytidyl-deoxyguanosine dinucleotide (CpG)-containing oligodeoxynucleotides (ODN) was used as an immuno-adjuvant to improve antibody responses. In preparation for a Phase I human trial, we elucidated potential contributions by which the sepsis vaccine (J5dLPS-OMP) and CpG ODN might enhance the antibody response and provide evidence that the generation of immune responses is Toll-like receptor (TLR) dependent. Toll-like receptor 2, TLR4, and TLR9 were each essential for generating robust cytokine and antibody responses. The signature cytokine of dendritic cells, interleukin-12, was one of the cytokines that demonstrated synergy with the optimal TLR ligand/ engagement combination. We conclude that the involvement of multiple TLRs upon immunization was critical for the generation of optimal antibody responses. These observations provide further evidence for the inclusion of innate immune-based adjuvants during the development of next-generation vaccines. PMID:19822632

  10. Polymorphisms within Toll-like receptors are associated with systemic lupus erythematous in a cohort of Danish females

    Laska, Magdalena Janina; Troldborg, Anne; Hansen, Bettina; Stengaard-Pedersen, Kristian; Junker, Michael Peter; Nexø, Bjørn Andersen; Voss, Anne

    2013-01-01

    -nucleotide polymorphisms (SNPs) was performed using Sequenom Multiplex technology. In addition, the mRNA expression of TLRs in PBMCs from 56 SLE patients and 56 healthy controls was studies by quantitative real-time PCR. RESULTS: We found a genetic association with SLE and three SNPs located within the TLR3, TLR8 and TLR9...... results obtained from a female lupus population of Danish ancestry suggest that variations in TLR3, TLR8 and TLR9 genes are implicated in the pathogenesis of the disease. If these polymorphisms are associated with innate immune dysfunction they may add to the growing field of theoretically well founded......OBJECTIVES: Toll-like receptors (TLRs) are pattern-associated receptors in innate immunity that may be involved in the recognition of self-antigens and the production of pathogenic autoantibodies. This study was undertaken to examine whether polymorphisms of TLR genes are associated with SLE and to...

  11. DMPD: How Toll-like receptors signal: what we know and what we don't know. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 16343886 How Toll-like receptors signal: what we know and what we don't know. O'Nei...like receptors signal: what we know and what we don't know. PubmedID 16343886 Title How Toll-like receptors signal: what... we know and what we don't know. Authors O'Neill LA. Publication Curr...ll LA. Curr Opin Immunol. 2006 Feb;18(1):3-9. Epub 2005 Dec 15. (.png) (.svg) (.html) (.csml) Show How Toll-

  12. Garlic (Allium sativum) Extracts Inhibits Lipopolysaccharide-Induced Toll-Like Receptor 4 Dimerization

    Garlic has been used as a folk medicine for a long history. Numerous studies demonstrated that garlic extracts and its sulfur-containing compounds inhibit nuclear factor-kappa B (NF-kB) activation induced by various receptor agonist including lipopolysaccharide (LPS). These effects suggest that garl...

  13. Hypoxia attenuates inflammatory mediators production induced by Acanthamoeba via Toll-like receptor 4 signaling in human corneal epithelial cells

    Pan, Hong [Department of Ophthalmology, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China); The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China); Wu, Xinyi, E-mail: xywu8868@163.com [Department of Ophthalmology, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer Hypoxia attenuates Acanthamoeba-induced the production of IL-8 and IFN-{beta}. Black-Right-Pointing-Pointer Hypoxia inhibits TLR4 expression in a time-dependent manner in HCECs. Black-Right-Pointing-Pointer Hypoxia inhibits Acanthamoeba-induced the activation of NF-{kappa}B and ERK1/2 in HCECs. Black-Right-Pointing-Pointer Hypoxia decreases Acanthamoeba-induced inflammatory response via TLR4 signaling. Black-Right-Pointing-Pointer LPS-induced the secretion of IL-6 and IL-8 is abated by hypoxia via TLR4 signaling. -- Abstract: Acanthamoeba keratitis (AK) is a vision-threatening corneal infection that is intimately associated with contact lens use which leads to hypoxic conditions on the corneal surface. However, the effect of hypoxia on the Acanthamoeba-induced host inflammatory response of corneal epithelial cells has not been studied. In the present study, we investigated the effect of hypoxia on the Acanthamoeba-induced production of inflammatory mediators interleukin-8 (IL-8) and interferon-{beta} (IFN-{beta}) in human corneal epithelial cells and then evaluated its effects on the Toll-like receptor 4 (TLR4) signaling, including TLR4 and myeloid differentiation primary response gene (88) (MyD88) expression as well as the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-{kappa}B) and extracellular signal-regulated kinases 1/2 (ERK1/2). We then studied the effect of hypoxia on a TLR4-specific inflammatory response triggered by the TLR4 ligand lipopolysaccharide (LPS). Our data showed that hypoxia significantly decreased the production of IL-8 and IFN-{beta}. Furthermore, hypoxia attenuated Acanthamoeba-triggered TLR4 expression as well as the activation of NF-{kappa}B and ERK1/2, indicating that hypoxia abated Acanthamoeba-induced inflammatory responses by affecting TLR4 signaling. Hypoxia also inhibited LPS-induced IL-6 and IL-8 secretion, myeloid differentiation primary response gene (88

  14. Crucial role of Toll-like receptors in the zinc/nickel-induced inflammatory response in vascular endothelial cells

    Tsou, Tsui-Chun, E-mail: tctsou@nhri.org.tw [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 350, Taiwan (China); Liou, Saou-Hsing; Yeh, Szu-Ching; Tsai, Feng-Yuan [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 350, Taiwan (China); Chao, How-Ran [Emerging Compounds Research Center, Department of Environmental Science and Engineering, National Pingtung University and Science and Technology, Neipu, Pingtung 912, Taiwan (China)

    2013-12-15

    Our previous studies indicated that zinc induced inflammatory response in both vascular endothelial cells and promonocytes. Here, we asked if other metals could cause the similar effect on vascular endothelial cells and tried to determine its underlying mechanism. Following screening of fifteen metals, zinc and nickel were identified with a marked proinflammatory effect, as determined by ICAM-1 and IL-8 induction, on human umbilical vein endothelial cells (HUVECs). Inhibiting protein expression of myeloid differentiation primary response protein-88 (MyD88), a Toll-like receptor (TLR) adaptor acting as a TLR-signaling transducer, significantly attenuated the zinc/nickel-induced inflammatory response, suggesting the critical roles of TLRs in the inflammatory response. Blockage of TLR-4 signaling by CLI-095, a TLR-4 inhibitor, completely inhibited the nickel-induced ICAM-1 and IL-8 expression and NFκB activation. The same CLI-095 treatment significantly blocked the zinc-induced IL-8 expression, however with no significant effect on the ICAM-1 expression and a minor inhibitory effect on the NFκB activation. The finding demonstrated the differential role of TLR-4 in regulation of the zinc/nickel-induced inflammatory response, where TLR-4 played a dominant role in NFκB activation by nickel, but not by zinc. Moreover, inhibition of NFκB by adenovirus-mediated IκBα expression and Bay 11-7025, an inhibitor of cytokine-induced IκB-α phosphorylation, significantly attenuated the zinc/nickel-induced inflammatory responses, indicating the critical of NFκB in the process. The study demonstrates the crucial role of TLRs in the zinc/nickel-induced inflammatory response in vascular endothelial cells and herein deciphers a potential important difference in NFκB activation via TLRs. The study provides a molecular basis for linkage between zinc/nickel exposure and pathogenesis of the metal-related inflammatory vascular disease. - Highlights: • Both zinc and nickel cause

  15. Involvement of Toll-like receptor 2 and epidermal growth factor receptor signaling in epithelial expression of airway remodeling factors.

    Homma, Tetsuya; Kato, Atsushi; Sakashita, Masafumi; Norton, James E; Suh, Lydia A; Carter, Roderick G; Schleimer, Robert P

    2015-04-01

    Staphylococcus aureus (SA) colonization and infection is common, and may promote allergic or inflammatory airway diseases, such as asthma, cystic fibrosis, and chronic rhinosinusitis by interacting with airway epithelial cells. Airway epithelial cells not only comprise a physical barrier, but also play key roles in immune, inflammatory, repair, and remodeling responses upon encounters with pathogens. To elucidate the impact of SA on epithelial-mediated remodeling of allergic airways, we tested the hypothesis that SA can enhance the remodeling process. Normal human bronchial epithelial (NHBE) cells were stimulated with heat-killed SA (HKSA) or transforming growth factor (TGF) α. Cell extracts were collected to measure mRNA (real-time RT-PCR) and signaling molecules (Western blot); supernatants were collected to measure protein (ELISA) after 24 hours of stimulation. Epidermal growth factor receptor (EGFR) signaling inhibition experiments were performed using a specific EGFR kinase inhibitor (AG1478) and TGF-α was blocked with an anti-TGF-α antibody. HKSA induced both mRNA and protein for TGF-α and matrix metalloproteinase (MMP) 1 from NHBE cells by a Toll-like receptor 2-dependent mechanism. Recombinant human TGF-α also induced mRNA and protein for MMP-1 from NHBE cells; anti-TGF-α antibody inhibited HKSA-induced MMP-1, suggesting that endogenous TGF-α mediates the MMP-1 induction by HKSA. HKSA-induced MMP-1 expression was suppressed when a specific EGFR kinase inhibitor was added, suggesting that EGFR signaling was mediating the HKSA-induced MMP-1 release. Exposure or colonization by SA in the airway may enhance the remodeling of tissue through a TGF-α-dependent induction of MMP-1 expression, and may thereby promote remodeling in airway diseases in which SA is implicated, such as asthma and chronic rhinosinusitis. PMID:25180535

  16. Toll-like receptor 4 knockout ameliorates neuroinflammation due to lung-brain interaction in mechanically ventilated mice.

    Chen, Ting; Chen, Chang; Zhang, Zongze; Zou, Yufeng; Peng, Mian; Wang, Yanlin

    2016-08-01

    Toll-like receptor 4 (TLR4) is a crucial receptor in the innate immune system, and increasing evidence supports its role in inflammation, stress, and tissue injury, including injury to the lung and brain. We aimed to investigate the effects of TLR4 on neuroinflammation due to the lung-brain interaction in mechanically ventilated mice. Male wild-type (WT) C57BL/6 and TLR4 knockout (TLR4 KO) mice were divided into three groups: (1) control group (C): spontaneous breathing; (2) anesthesia group (A): spontaneous breathing under anesthesia; and (3) mechanical ventilation group (MV): 6h of MV under anesthesia. The behavioral responses of mice were tested with fear conditioning tests. The histological changes in the lung and brain were assessed using hematoxylin-eosin (HE) staining. The level of TLR4 mRNA in tissue was measured using reverse transcription-polymerase chain reaction (RT-PCR). The levels of inflammatory cytokines were measured with an enzyme-linked immunosorbent assay (ELISA). Microgliosis, astrocytosis, and the TLR4 immunoreactivity in the hippocampus were measured by double immunofluorescence. MV mice exhibited impaired cognition, and this impairment was less severe in TLR4 KO mice than in WT mice. In WT mice, MV increased TLR4 mRNA expression in the lung and brain. MV induced mild lung injury, which was prevented in TLR4 KO mice. MV mice exhibited increased levels of inflammatory cytokines, increased microglia and astrocyte activation. Microgliosis was alleviated in TLR4 KO mice. MV mice exhibited increased TLR4 immunoreactivity, which was expressed in microglia and astrocytes. These results demonstrate that TLR4 is involved in neuroinflammation due to the lung-brain interaction and that TLR4 KO ameliorates neuroinflammation due to lung-brain interaction after prolonged MV. In addition, Administration of a TLR4 antagonist (100μg/mice) to WT mice also significantly attenuated neuroinflammation of lung-brain interaction due to prolonged MV. TLR4 antagonism

  17. Toll-like receptor 4-dependent upregulation of cytokines in a transgenic mouse model of Alzheimer's disease

    Li Ling

    2008-05-01

    Full Text Available Abstract Background Aβ deposits in the brains of patients with Alzheimer's disease (AD are closely associated with innate immune responses such as activated microglia and increased cytokines. Accumulating evidence supports the hypothesis that innate immune/inflammatory responses play a pivotal role in the pathogenesis of AD: either beneficial or harmful effects on the AD progression. The molecular mechanisms by which the innate immune system modulates the AD progression are not well understood. Toll-like receptors (TLRs are first-line molecules for initiating the innate immune responses. When activated through TLR signaling, microglia respond to pathogens and damaged host cells by secreting chemokines and cytokines and express the co-stimulatory molecules needed for protective immune responses to pathogens and efficient clearance of damaged tissues. We previously demonstrated that an AD mouse model homozygous for a destructive mutation of TLR4 has increases in diffuse and fibrillar Aβ deposits as well as buffer-soluble and insoluble Aβ in the brain as compared with a TLR4 wild-type AD mouse model. Here, we investigated the roles of TLR4 in Aβ-induced upregulation of cytokines and chemokines, Aβ-induced activation of microglia and astrocytes and Aβ-induced immigration of leukocytes. Methods Using the same model, levels of cytokines and chemokines in the brain were determined by multiplex cytokine/chemokine array. Activation of microglia and astrocytes and immigration of leukocytes were determined by immunoblotting and immunohistochemistry followed by densitometry and morphometry, respectively. Results Levels of tumor necrosis factor (TNF-α, interleukin (IL-1β, IL-10 and IL-17 in the brains of TLR4 wild-type AD mice were significantly higher than those in TLR4 wild-type non-transgenic littermates. Such increases in cytokines were not found in TLR4 mutant AD mice as compared with TLR4 mutant non-transgenic littermates. Although expression

  18. Anti-inflammatory effects of royal poinciana through inhibition of toll-like receptor 4 signaling pathway.

    Patra, Satyajit; Muthuraman, Meenakshi Sundaram; Meenu, M; Priya, Padma; Pemaiah, Brindha

    2016-05-01

    Inflammation is part of the non-specific immune response that occurs in reaction to any type of bodily injury. In some disorders the inflammatory process, which under normal conditions is self-limiting, becomes continuous and chronic inflammatory diseases develop subsequently including cardiovascular diseases, diabetes, cancer etc. Barks of Delonix regia is used traditionally in the treatment of inflammatory diseases. Therefore, in this study we evaluated the therapeutic potential of D. regia ethanol extract and its active constituent β-Elemene with special interest in inflammation model using standard in vivo anti-inflammatory models: Carrageenan-induced paw edema, Cotton pellet granuloma, and Acetic acid-induced vascular permeability. To explicate the mechanism of action for the possible anti-inflammatory activity, we determined the level of major inflammatory mediators (NO, iNOS, COX-2-dependent prostaglandin E2 or PGE2), and pro-inflammatory cytokines (TNF-a, IL-1b, IL-6, and IL-12). Additionally, we determined the toll-like receptor 4 (TLR4), Myeloid differentiation primary response gene 88 (MyD88), by mRNA expression in drug treated LPS-induced murine macrophage model. To explore the mechanism of anti-inflammatory activity, we evaluated expression of c-Jun N-terminal kinases (JNK), nuclear factor kappa-B cells (NF-kB), and NF-kB inhibitor alpha (IK-Ba). Furthermore, we determined the acute and sub-acute toxicity of D. regia extract in BALB/c mice. This study established a significant anti-inflammatory activity of D. regia extract and β-Elemene along with the inhibition of TNF-a, IL-1b, IL-6 and IL-12 expressions. Further, the expression of TLR4, NF-kBp65, MyD88, iNOS and COX-2 molecules were reduced in drug-treated groups, but not in the LPS-stimulated untreated or control groups, Thus, our results collectively indicated that the D. regia extract and β-Elemene can efficiently inhibit inflammation. PMID:26971223

  19. Toll-Like Receptors and Cytokines as Surrogate Biomarkers for Evaluating Vaginal Immune Response following Microbicide Administration

    Sadhana M. Gupta

    2008-01-01

    Full Text Available Topical microbicides are intended for frequent use by women in reproductive age. Hence, it is essential to evaluate their impact on mucosal immune function in the vagina. In the present study, we evaluated nisin, a naturally occurring antimicrobial peptide (AMP, for its efficacy as an intravaginal microbicide. Its effect on the vaginal immune function was determined by localizing Toll-like receptors (TLRs-3, 9 and cytokines (IL-4, 6 , 10 and TNF-α in the rabbit cervicovaginal epithelium following intravaginal administration of high dose of nisin gel for 14 consecutive days. The results revealed no alteration in the expression of TLRs and cytokines at both protein and mRNA levels. However, in SDS gel-treated group, the levels were significantly upregulated with the induction of NF-κB signalling cascade. Thus, TLRs and cytokines appear as sensitive indicators for screening immunotoxic potential of candidate microbicides.

  20. Induction of inflammatory cytokines and toll-like receptors in chickens infected with avian H9N2 influenza virus

    Nang Nguyen

    2011-05-01

    Full Text Available Abstract H9N2 influenza virus is endemic in many Asian countries and is regarded as a candidate for the next human pandemic. Knowledge of the induction of inflammatory responses and toll-like receptors (TLRs in chickens infected with H9N2 is limited. Here, we show that H9N2 induces pro-inflammatory cytokines such as transforming growth factor-beta 3; tumor necrosis factor-alpha; interferon-alpha, -beta, and gamma; and TLR 1, 2, 3, 4, 5, 7, and 15 in trachea, lung, and intestine of infected chickens. In the lung, TLR-15 was dominantly induced. Taken together, it seems that H9N2 infections efficiently induce inflammatory cytokines and TLRs in trachea, lung and intestine of chickens.

  1. Toll-like receptor pre-stimulation protects mice against lethal infection with highly pathogenic influenza viruses

    Makino Akiko

    2011-03-01

    Full Text Available Abstract Since the beginning of the 20th century, humans have experienced four influenza pandemics, including the devastating 1918 'Spanish influenza'. Moreover, H5N1 highly pathogenic avian influenza (HPAI viruses are currently spreading worldwide, although they are not yet efficiently transmitted among humans. While the threat of a global pandemic involving a highly pathogenic influenza virus strain looms large, our mechanisms to address such a catastrophe remain limited. Here, we show that pre-stimulation of Toll-like receptors (TLRs 2 and 4 increased resistance against influenza viruses known to induce high pathogenicity in animal models. Our data emphasize the complexity of the host response against different influenza viruses, and suggest that TLR agonists might be utilized to protect against lethality associated with highly pathogenic influenza virus infection in humans.

  2. Association of Toll-Like Receptor Signaling and Reactive Oxygen Species: A Potential Therapeutic Target for Posttrauma Acute Lung Injury

    Meng Xiang

    2010-01-01

    Full Text Available Acute lung injury (ALI frequently occurs in traumatic patients and serves as an important component of systemic inflammatory response syndrome (SIRS. Hemorrhagic shock (HS that results from major trauma promotes the development of SIRS and ALI by priming the innate immune system for an exaggerated inflammatory response. Recent studies have reported that the mechanism underlying the priming of pulmonary inflammation involves the complicated cross-talk between Toll-like receptors (TLRs and interactions between neutrophils (PMNs and alveolar macrophages (AMϕ as well as endothelial cells (ECs, in which reactive oxygen species (ROS are the key mediator. This paper summarizes some novel mechanisms underlying HS-primed lung inflammation focusing on the role of TLRs and ROS, and therefore suggests a new therapeutic target for posttrauma ALI.

  3. Expression of Toll-like receptor 9 (TLR9) in the lungs and lymphoid tissue of pigs.

    Kuzemtseva, Liudmila; Pérez, Mónica; Mateu, Enric; Segalés, Joaquim; Darwich, Laila

    2015-02-01

    The pattern of distribution of Toll-like receptor 9 (TLR9) in different tissues varies between species. The aim of the present study was to describe the distribution of TLR9 expression in selected tissues and organs of healthy pigs at 3 weeks and 3 months of age. Representative formalin-fixed samples of lung, thymus and secondary lymphoid tissues were evaluated by immunohistochemistry. TLR9 positive staining was observed in epithelial cells, vascular endothelium and myoepithelial-like cells, as well as in cells of the alveolar septa of the lung. Antigen presenting cells of perifollicular zones (interdigitating, macrophage and dendritic-like cells) of the Peyer's patches, lymph nodes, spleen and thymus were also immunoreactive for TLR9. No differences were seen in TLR9 protein expression in tissues from the two age groups. PMID:25576141

  4. Cancers take their Toll--the function and regulation of Toll-like receptors in cancer cells

    Chen, R; Alvero, A B; Silasi, D-A; Steffensen, K D; Mor, G

    2008-01-01

    proliferation, would also be key factors in regulating and enhancing cancer progression. The TLR pathways, which play a critical role in tissue repair, are also key regulators in cancer progression as well as chemoresistance. TLRs serve as cell surface sensors that can initiate pathways leading to proliferation...... and chemoresistance; as well as mediators that are able to regulate the infiltrating immune cells to provide further support for cancer progression.......Cancer could be deemed as an abnormal and uncontrolled tissue repair process. Therefore, it would not be surprising that factors that function in the tissue repair process, such as cytokines, chemokines, growth factors and Toll-like receptor (TLR) ligands, as well as growth signals for compensatory...

  5. Chlorogenic acid reduces liver inflammation and fibrosis through inhibition of toll-like receptor 4 signaling pathway

    Highlights: ► Chlorogenic acid decreased serum transaminase level and increased albumin level. ► Chlorogenic acid attenuated CCl4-induced liver collagen deposition. ► Chlorogenic acid ameliorated CCl4-induced inflammatory response. ► Chlorogenic acid inhibited the activation of TLR4/NF-κB signaling in liver. -- Abstract: Chlorogenic acid (CGA) is a type of polyphenol with anti-inflammatory, antioxidant activities. Our previous studies showed CGA could efficiently inhibit carbon tetrachloride (CCl4)-induced liver fibrosis in rats. However, the specific underlying mechanism remains unclear. The aim of this study is to investigate the effects of CGA on liver inflammation and fibrosis induced by CCl4 and whether they are related to inhibition of toll-like receptor 4 (TLR4) signaling pathway. Male Sprague-Dawley (SD) rats were administrated CCl4 together with or without CGA for 8 weeks. Histopathological and biochemical analyses were carried out. The mRNA and protein expression levels of proinflammatory and profibrotic mediators were detected by RT-PCR and Western blot, respectively. The levels of serum proinflammatory cytokines were detected by ELISA. CGA significantly attenuated CCl4-induced liver damage and symptoms of liver fibrosis, accompanied by reduced serum transaminase levels, collagen I and α-smooth muscle actin (α-SMA) expression. As compared with the CCl4-treated group, the expression levels of TLR4, myeloid differentiation factor 88 (MyD88), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were reduced in the treatment group of CCl4 and CGA, whereas bone morphogenetic protein and activin membrane-bound inhibitor (Bambi) expression was increased. CGA also suppressed CCl4 induced nuclear factor-κB (NF-κB) activation. Moreover, the hepatic mRNA expression and serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were significantly increased in CCl4-treated rats and attenuated by co

  6. Group X Secretory Phospholipase A2 Enhances Toll-Like Receptor 4 Signaling in Macrophages

    Shridas, Preetha; Bailey, William M.; Talbott, Kayla R; Oslund, Rob C.; Gelb, Michael H; Webb, Nancy R.

    2011-01-01

    Secretory phospholipase A2’s (sPLA2) hydrolyze glycerophospholipids to liberate lysophospholipids and free fatty acids. Although Group X (GX) sPLA2 is recognized as the most potent mammalian sPLA2 in vitro, its precise physiological function(s) remain unclear. We recently reported that GX sPLA2 suppresses activation of the Liver X receptor (LXR) in macrophages, resulting in reduced expression of LXR-responsive genes including ABCA1 and ABCG1, and a consequent decrease in cellular cholesterol ...

  7. Knockout of Toll-Like Receptors 2 and 4 Prevents Renal Ischemia-Reperfusion-Induced Cardiac Hypertrophy in Mice

    Trentin-Sonoda, Mayra; da Silva, Rogério Cirino; Kmit, Fernanda Vieira; Abrahão, Mariana Vieira; Monnerat Cahli, Gustavo; Brasil, Guilherme Visconde; Muzi-Filho, Humberto; Silva, Paulo André; Tovar-Moll, Fernanda Freire; Vieyra, Adalberto; Medei, Emiliano; Carneiro-Ramos, Marcela Sorelli

    2015-01-01

    We investigated whether the pathways linked to Toll-like receptors 2 and 4 (TLRs) are involved in renal ischemia-reperfusion (I/R)-induced cardiac hypertrophy. Wild type (WT) C57BL/6J, TLR2-/- and TLR4-/- mice were subjected to left kidney ischemia for 60 min followed by reperfusion for 5, 8, 12 and 15 days. Proton density magnetic resonance showed alterations in the injured kidney from WT mice, together with signs of parenchymal edema and higher levels of vimentin mRNA, accompanied by: (i) small, but significant, increase in serum urea after 24 h, (ii) 100% increase in serum creatinine at 24 h. A serum peak of inflammatory cytokines occurred after 5 days of reperfusion. Heart weight/body weight and heart weight/tibia length ratios increased after 12 and 15 days of reperfusion, respectively. Cardiac hypertrophy markers, B-type natriuretic peptide (BNP) and α-actin, left ventricle mass, cardiac wall thickness and myocyte width increased after 15 days of reperfusion, together with longer QTc and action potential duration. Cardiac TLRs, MyD88, HSP60 and HSP70 mRNA levels also increased. After 15 days of reperfusion, absence of TLRs prevented cardiac hypertrophy, as reflected by similar values of left ventricular cardiac mass and heart weight/body weight ratio compared to the transgenic Sham. Renal tissular injury also ameliorated in both knockout mice, as revealed by the comparison of their vimentin mRNA levels with those found in the WT on the same day after I/R. The I/R TLR2-/- group had TNF-α, IFN-γ and IL-1β levels similar to the non-I/R group, whereas the TLR4-/- group conserved the p-NF-κB/NF- κB ratio contrasting with that found in TLR2-/-. We conclude: (i) TLRs are involved in renal I/R-induced cardiac hypertrophy; (ii) absence of TLRs prevents I/R-induced cardiac hypertrophy, despite renal lesions seeming to evolve towards those of chronic disease; (iii) TLR2 and TLR4 selectively regulate the systemic inflammatory profile and NF- κB activation. PMID

  8. Toll-like receptor 4 knockout alleviates paraquat-induced cardiomyocyte contractile dysfunction through an autophagy-dependent mechanism.

    Wang, Shuyi; Zhu, Xiaoling; Xiong, Lize; Zhang, Yingmei; Ren, Jun

    2016-08-22

    Paraquat, a quarternary nitrogen herbicide, is a toxic prooxidant leading to multi-organ failure including the heart although the underlying mechanism remains poorly understood. This study was designed to examine the role of the innate proinflammatory mediator toll-like receptor 4 (TLR4) in paraquat-induced cardiac contractile anomalies and the underlying mechanisms involved with a focus on autophagy, a conservative machinery governing protein and organelle degradation and recycling for cardiac homeostasis. Wild-type (WT) and TLR4 knockout (TLR4(-/-)) mice were challenged with paraquat (45mg/kg, i.p.) for 48h. Paraquat challenge did not affect mRNA levels of TLR2, TLR4 and TLR9 in WT mice nor did paraquat treatment alter TREM-1 levels. Paraquat challenge elicited cardiac mechanical defects including compromised cardiomyocyte contractile function, intracellular Ca(2+) handling, and overt autophagy as manifested by increased LC3BII-to-LC3BI ratio, Atg5, Atg7 and p62 levels. Interestingly, TLR4 knockout significantly attenuated paraquat-induced cardiac contractile and intracellular Ca(2+) derangement as well as alterations of autophagy markers. Paraquat-elicited changes in cardiac autophagy markers (LC3BII, LC3BII-to-LC3BI ratio and p62) were augmented by lysosomal inhibition using bafilomycin A1 in WT mice. TLR4 knockout significantly attenuated or negated paraquat-elicited increase in LC3BII, LC3BII-to-LC3BI ratio and p62 levels in the presence of lysosomal inhibition. In addition, paraquat challenge promoted phosphorylation of AMPK while suppressing the phosphorylation of mTOR and ULK1 (the autophagy inhibitory Ser(757)), the effects of which were significantly attenuated by TLR4 ablation. In vitro study revealed that AMPK activation using AICAR or mTOR inhibition using rapamycin effectively negated the beneficial cardiomyocyte mechanical effects of TLR4 inhibition (CLI-095) against paraquat toxicity, supporting a permissive role for AMPK-mTOR in TLR4 inhibition

  9. Toll-like receptor 4-mediated lymphocyte influx induces neonatal necrotizing enterocolitis.

    Egan, Charlotte E; Sodhi, Chhinder P; Good, Misty; Lin, Joyce; Jia, Hongpeng; Yamaguchi, Yukihiro; Lu, Peng; Ma, Congrong; Branca, Maria F; Weyandt, Samantha; Fulton, William B; Niño, Diego F; Prindle, Thomas; Ozolek, John A; Hackam, David J

    2016-02-01

    The nature and role of the intestinal leukocytes in necrotizing enterocolitis (NEC), a severe disease affecting premature infants, remain unknown. We now show that the intestine in mouse and human NEC is rich in lymphocytes that are required for NEC development, as recombination activating gene 1–deficient (Rag1–/–) mice were protected from NEC and transfer of intestinal lymphocytes from NEC mice into naive mice induced intestinal inflammation. The intestinal expression of the lipopolysaccharide receptor TLR4, which is higher in the premature compared with full-term human and mouse intestine, is required for lymphocyte influx through TLR4-mediated upregulation of CCR9/CCL25 signaling. TLR4 also mediates a STAT3-dependent polarization toward increased proinflammatory CD3+CD4+IL-17+ and reduced tolerogenic Foxp3+ Treg lymphocytes (Tregs). Th17 lymphocytes were required for NEC development, as inhibition of STAT3 or IL-17 receptor signaling attenuated NEC in mice, while IL-17 release impaired enterocyte tight junctions, increased enterocyte apoptosis, and reduced enterocyte proliferation, leading to NEC. Importantly, TLR4-dependent Th17 polarization could be reversed by the enteral administration of retinoic acid, which induced Tregs and decreased NEC severity. These findings identify an important role for proinflammatory lymphocytes in NEC development via intestinal epithelial TLR4 that could be reversed through dietary modification. PMID:26690704

  10. DMPD: Signal transduction pathways mediated by the interaction of CpG DNA withToll-like receptor 9. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 14751759 Signal transduction pathways mediated by the interaction of CpG DNA withTo...;16(1):17-22. (.png) (.svg) (.html) (.csml) Show Signal transduction pathways mediated by the interaction of... CpG DNA withToll-like receptor 9. PubmedID 14751759 Title Signal transduction pa

  11. Absence of Toll-Like Receptor 4 Signaling Results in Delayed Yersinia enterocolitica YopP-Induced Cell Death of Dendritic Cells

    Gröbner, S.; Schulz, S.; Adkins, Irena; Gunst, D. S. J.; Waibel, M.; Wesselborg, S.; Borgmann, S.; Autenrieth, I. B.

    2007-01-01

    Roč. 75, č. 1 (2007), s. 512-517. ISSN 0019-9567 Institutional research plan: CEZ:AV0Z50200510 Keywords : yersinia enterocolitica * toll-like receptor 4 * dendritic cells Subject RIV: EC - Immunology Impact factor: 3.996, year: 2007

  12. Distinct uptake mechanisms but similar intracellular processing of two different toll-like receptor ligand-peptide conjugates in dendritic cells.

    Khan, S.; Bijker, M.S.; Weterings, J.J.; Tanke, H.J.; Adema, G.J.; Hall, T. van; Drijfhout, J.W.; Melief, C.J.; Overkleeft, H.S.; Marel, G.A. van der; Filippov, D.V.; Burg, S.H. van der; Ossendorp, F.

    2007-01-01

    Covalent conjugation of Toll-like receptor ligands (TLR-L) to synthetic antigenic peptides strongly improves antigen presentation in vitro and T lymphocyte priming in vivo. These molecularly well defined TLR-L-peptide conjugates, constitute an attractive vaccination modality, sharing the peptide ant

  13. Increased expression of toll-like receptor 4 and inflammatory cytokines, interleukin-6 in particular, in islets from a mouse model of obesity and type 2 diabetes

    Ladefoged, Mette; Buschard, Karsten; Hansen, Ann Maria Kruse

    2013-01-01

    Toll-like receptor 4 (TLR4) has received much attention in the recent years due to its role in development of insulin resistance in type 2 diabetes mellitus. Its expression is elevated in fat and muscle from insulin-resistant mice. Several cells of the pancreatic islets, including β-cells and...

  14. Characterization of Toll-like receptors in primary lung epithelial cells: strong impact of the TLR3 ligand poly(I:C on the regulation of Toll-like receptors, adaptor proteins and inflammatory response

    Weith Andreas

    2005-11-01

    Full Text Available Abstract Background Bacterial and viral exacerbations play a crucial role in a variety of lung diseases including COPD or asthma. Since the lung epithelium is a major source of various inflammatory mediators that affect the immune response, we analyzed the inflammatory reaction of primary lung epithelial cells to different microbial molecules that are recognized by Toll-like receptors (TLR. Methods The effects of TLR ligands on primary small airway epithelial cells were analyzed in detail with respect to cytokine, chemokine and matrix metalloproteinase secretion. In addition, the regulation of the expression of TLRs and their adaptor proteins in small airway epithelial cells was investigated. Results Our data demonstrate that poly(I:C, a synthetic analog of viral dsRNA, mediated the strongest proinflammatory effects among the tested ligands, including an increased secretion of IL-6, IL-8, TNF-α, GM-CSF, GRO-α, TARC, MCP-1, MIP-3α, RANTES, IFN-β, IP-10 and ITAC as well as an increased release of MMP-1, MMP-8, MMP-9, MMP-10 and MMP-13. Furthermore, our data show that poly(I:C as well as type-1 and type-2 cytokines have a pronounced effect on the expression of TLRs and molecules involved in TLR signaling in small airway epithelial cells. Poly(I:C induced an elevated expression of TLR1, TLR2 and TLR3 and increased the gene expression of the general TLR adaptor MyD88 and IRAK-2. Simultaneously, poly(I:C decreased the expression of TLR5, TLR6 and TOLLIP. Conclusion Poly(I:C, an analog of viral dsRNA and a TLR3 ligand, triggers a strong inflammatory response in small airway epithelial cells that is likely to contribute to viral exacerbations of pulmonary diseases like asthma or COPD. The pronounced effects of poly(I:C on the expression of Toll-like receptors and molecules involved in TLR signaling is assumed to influence the immune response of the lung epithelium to viral and bacterial infections. Likewise, the regulation of TLR expression by type

  15. Toll-like receptor 4 mutant and null mice retain morphine-induced tolerance, hyperalgesia, and physical dependence.

    Theresa Alexandra Mattioli

    Full Text Available The innate immune system modulates opioid-induced effects within the central nervous system and one target that has received considerable attention is the toll-like receptor 4 (TLR4. Here, we examined the contribution of TLR4 in the development of morphine tolerance, hyperalgesia, and physical dependence in two inbred mouse strains: C3H/HeJ mice which have a dominant negative point mutation in the Tlr4 gene rendering the receptor non-functional, and B10ScNJ mice which are TLR4 null mutants. We found that neither acute antinociceptive response to a single dose of morphine, nor the development of analgesic tolerance to repeated morphine treatment, was affected by TLR4 genotype. Likewise, opioid induced hyperalgesia and opioid physical dependence (assessed by naloxone precipitated withdrawal were not altered in TLR4 mutant or null mice. We also examined the behavioural consequence of two stereoisomers of naloxone: (- naloxone, an opioid receptor antagonist, and (+ naloxone, a purported antagonist of TLR4. Both stereoisomers of naloxone suppressed opioid induced hyperalgesia in wild-type control, TLR4 mutant, and TLR4 null mice. Collectively, our data suggest that TLR4 is not required for opioid-induced analgesic tolerance, hyperalgesia, or physical dependence.

  16. The rationale for combined chemo/immunotherapy using a Toll-like receptor 3 (TLR3) agonist and tumour-derived exosomes in advanced ovarian cancer.

    Adams, M; Navabi, H; Croston, D; Coleman, S; Tabi, Z; Clayton, A; Jasani, B; Mason, M D

    2005-03-18

    A clinical trial employing an immunotherapeutic approach based on the use of a Toll-like receptor 3 (TLR3) agonist and tumour-derived exosomes carrying tumour-associated antigens is planned in advanced ovarian cancer in conjunction with conventional first line chemotherapy. Most patients with ovarian cancer present with advanced disease and despite high initial response rate to chemotherapy the majority will relapse within 2 years with poor overall survival. Tumour antigen-specific T cells are naturally occurring in ovarian cancer patients and T cell infiltration of the tumour is highly prognostic. Novel immunotherapy to expand and activate tumour antigen-specific T cells combined with adjuvant treatment to overcome tumour-induced immunosuppression is considered to be therapeutically beneficial. The rationale for adopting such a combined approach is discussed here. PMID:15755631

  17. Corticotropin-Releasing Factor and Toll-Like Receptor Gene Expression Is Associated with Low-Grade Inflammation in Irritable Bowel Syndrome Patients with Depression

    Jizhong, Song; Qiaomin, Wang; Chao, Wang

    2016-01-01

    The mechanism of low-grade inflammation in irritable bowel syndrome (IBS) is unclear; our research concentrates on the involvement of the corticotropin-releasing factor (CRF) and Toll-like receptor (TLR) gene expression in the process of low-grade inflammation in IBS patients with depression. This study suggests more IBS patients are presenting with the states of depression and anxiety. IBS patients with depression have shown a lower grade inflammatory response and an imbalance of the inflammatory response. CRF1, CRF2, TLR2, and TLR4 in IBS patients with depression are significantly higher than those without depression and controls. Thus, activation of the CRF-TLR associated pathways produces an inflammatory reaction, which can concurrently affect the digestive tract and the CNS and induce the corresponding digestive and psychiatric symptoms.

  18. Species-specific engagement of human nucleotide oligomerization domain 2 (NOD)2 and Toll-like receptor (TLR) signalling upon intracellular bacterial infection

    Salem, M; Seidelin, J B; Eickhardt-Dalbøge, Steffen Robert;

    2015-01-01

    of MDP and further to determine the role of NOD2 gene variants for the bacterial recognition in CD. The response pattern to A-MDP, G-MDP, Mycobacterium segmatis (expressing mainly G-MDP) and M. segmatisΔnamH (expressing A-MDP), Listeria monocytogenes (LM) (an A-MDP-containing bacteria) and M. avium....... NOD2 mutations resulted in a low tumour necrosis factor (TNF)-α protein secretion following stimulation with LM. Contrary to this, TNF-α levels were unchanged upon MAP stimulation regardless of NOD2 genotype and MAP solely activated NOD2- and Toll-like receptor (TLRs)-pathway with an enhanced...... production of interleukin (IL)-1β and IL-10. In conclusion, the results indicate that CD-associated NOD2 deficiencies might affect the response towards a broader array of commensal and pathogenic bacteria expressing A-MDP, whereas they attenuate the role of mycobacteria in the pathogenesis of CD....

  19. Synthesis of anti-inflammatory α-and β-linked acetamidopyranosides as inhibitors of toll-like receptor 4 (TLR4)§

    Wipf, Peter; Eyer, Benjamin R.; Yamaguchi, Yukihiro; Zhang, Feng; Neal, Matthew D.; Sodhi, Chhinder P.; Good, Misty; Branca, Maria; Prindle, Thomas; Lu, Peng; Brodsky, Jeffrey L.; Hackam, David J.

    2014-01-01

    The low-molecular weight isopropyl 2-acetamido-α-glucoside 16 (C34) inhibits toll-like receptor 4 (TLR4) in enterocytes and macrophages in vitro, and reduces systemic inflammation in mouse models of endotoxemia and necrotizing enterocolitis. We used a copper(II)-mediated solvolysis of anomeric oxazolines and an acid-mediated conversion of β-glucosamine and β-galactosamine pentaacetates to generate analogs of 16 at the anomeric carbon and at C-4 of the pyranose ring. These compounds were evaluated for their influence on TLR4-mediated inflammatory signaling in cultured enterocytes and monocytes. Their efficacy was confirmed using a NF-kB-luciferase reporter mouse, thus establishing the first structure-activity relationship (SAR) study in this series and identifying the more efficacious isopropyl 2-acetamido-α-galactoside 17. PMID:26236050

  20. Inhibition of Toll-like receptor 2-mediated interleukin-8 production in Cystic Fibrosis airway epithelial cells via the alpha7-nicotinic acetylcholine receptor.

    Greene, Catherine M

    2010-01-01

    Cystic Fibrosis (CF) is an inherited disorder characterised by chronic inflammation of the airways. The lung manifestations of CF include colonization with Pseudomonas aeruginosa and Staphylococcus aureus leading to neutrophil-dominated airway inflammation and tissue damage. Inflammation in the CF lung is initiated by microbial components which activate the innate immune response via Toll-like receptors (TLRs), increasing airway epithelial cell production of proinflammatory mediators such as the neutrophil chemokine interleukin-8 (IL-8). Thus modulation of TLR function represents a therapeutic approach for CF. Nicotine is a naturally occurring plant alkaloid. Although it is negatively associated with cigarette smoking and cardiovascular damage, nicotine also has anti-inflammatory properties. Here we investigate the inhibitory capacity of nicotine against TLR2- and TLR4-induced IL-8 production by CFTE29o- airway epithelial cells, determine the role of alpha7-nAChR (nicotinic acetylcholine receptor) in these events, and provide data to support the potential use of safe nicotine analogues as anti-inflammatories for CF.

  1. Are Toll-Like Receptors and Decoy Receptors Involved in the Immunopathogenesis of Systemic Lupus Erythematosus and Lupus-Like Syndromes?

    Giuliana Guggino

    2012-01-01

    Full Text Available In this paper we focus our attention on the role of two families of receptors, Toll-like receptors (TLR and decoy receptors (DcR involved in the generation of systemic lupus erythematosus (SLE and lupus-like syndromes in human and mouse models. To date, these molecules were described in several autoimmune disorders such as rheumatoid arthritis, antiphospholipids syndrome, bowel inflammation, and SLE. Here, we summarize the findings of recent investigations on TLR and DcR and their role in the immunopathogenesis of the SLE.

  2. Evolutionary redesign of the Atlantic cod (Gadus morhua L.) Toll-like receptor repertoire by gene losses and expansions.

    Solbakken, Monica H; Tørresen, Ole K; Nederbragt, Alexander J; Seppola, Marit; Gregers, Tone F; Jakobsen, Kjetill S; Jentoft, Sissel

    2016-01-01

    Genome sequencing of the teleost Atlantic cod demonstrated loss of the Major Histocompatibility Complex (MHC) class II, an extreme gene expansion of MHC class I and gene expansions and losses in the innate pattern recognition receptor (PRR) family of Toll-like receptors (TLR). In a comparative genomic setting, using an improved version of the genome, we characterize PRRs in Atlantic cod with emphasis on TLRs demonstrating the loss of TLR1/6, TLR2 and TLR5 and expansion of TLR7, TLR8, TLR9, TLR22 and TLR25. We find that Atlantic cod TLR expansions are strongly influenced by diversifying selection likely to increase the detectable ligand repertoire through neo- and subfunctionalization. Using RNAseq we find that Atlantic cod TLRs display likely tissue or developmental stage-specific expression patterns. In a broader perspective, a comprehensive vertebrate TLR phylogeny reveals that the Atlantic cod TLR repertoire is extreme with regards to losses and expansions compared to other teleosts. In addition we identify a substantial shift in TLR repertoires following the evolutionary transition from an aquatic vertebrate (fish) to a terrestrial (tetrapod) life style. Collectively, our findings provide new insight into the function and evolution of TLRs in Atlantic cod as well as the evolutionary history of vertebrate innate immunity. PMID:27126702

  3. Comparison of Cellular Uptake and Inflammatory Response via Toll-Like Receptor 4 to Lipopolysaccharide and Titanium Dioxide Nanoparticles

    Akiyoshi Taniguchi

    2013-06-01

    Full Text Available The innate immune response is the earliest cellular response to infectious agents and mediates the interactions between microbes and cells. Toll-like receptors (TLRs play an important role in these interactions. We have already shown that TLRs are involved with the uptake of titanium dioxide nanoparticles (TiO2 NPs and promote inflammatory responses. In this paper, we compared role of cellular uptake and inflammatory response via TLR 4 to lipopolysaccharide (LPS and TiO2 NPs. In the case of LPS, LPS binds to LPS binding protein (LBP and CD 14, and then this complex binds to TLR 4. In the case of TiO2 NPs, the necessity of LBP and CD 14 to induce the inflammatory response and for uptake by cells was investigated using over-expression, antibody blocking, and siRNA knockdown experiments. Our results suggested that for cellular uptake of TiO2 NPs, TLR 4 did not form a complex with LBP and CD 14. In the TiO2 NP-mediated inflammatory response, TLR 4 acted as the signaling receptor without protein complex of LPS, LBP and CD 14. The results suggested that character of TiO2 NPs might be similar to the complex of LPS, LBP and CD 14. These results are important for development of safer nanomaterials.

  4. Toll-like receptor 2 of tongue sole Cynoglossus semilaevis: Signaling pathway and involvement in bacterial infection.

    Li, Xue-Peng; Sun, Li

    2016-04-01

    Toll-like receptor (TLR) 2 is a member of the TLR family that plays a pivotal role in innate immunity. In mammals, TLR2 is known to recognize specific microbial structures and trigger MyD88-dependent signaling to induce various cytokine responses. In this study, we examined the expression and function of the tongue sole Cynoglossus semilaevis TLR2, CsTLR2. CsTLR2 is composed of 898 amino acid residues and shares 25.6%-27.3% overall sequence identities with known teleost TLR2. CsTLR2 is a transmembrane protein with a toll/interleukin-1 receptor domain and eight leucine-rich repeats. Expression of CsTLR2 occurred in multiple tissues and was upregulated during bacterial infection. Stimulation of the CsTLR2 pathway led to enhanced expression of MyD88-dependent signaling molecules. Recombinant CsTLR2 (rCsTLR2) corresponding to the extracellular region was able to bind to a wide range of bacteria. Under both in vitro and in vivo conditions, rCsTLR2 significantly reduced bacterial infection. These observations add new insights into the signaling and function of teleost TLR2. PMID:26947353

  5. Live and heat-killed probiotic Lactobacillus casei Lbs2 protects from experimental colitis through Toll-like receptor 2-dependent induction of T-regulatory response.

    Thakur, Bhupesh Kumar; Saha, Piu; Banik, George; Saha, Dhira Rani; Grover, Sunita; Batish, Virender Kumar; Das, Santasabuj

    2016-07-01

    Inflammatory bowel disease (IBD) is a group of inflammatory disorders of the intestine caused by dysregulated T-cell mediated immune response against commensal microflora. Probiotics are reported as therapeutically effective against IBD. However, variable efficacy of the live probiotic strains, difference in survival and persistence in the gut between the strains and the lack of insight into the mechanisms of probiotic action limit optimal therapeutic efficacy. Our aims were to evaluate the lactobacillus strains isolated from the North Indian population for the generation of regulatory cells and cytokines in the intestine, to study their effects on pro-inflammatory mediators in the mouse model of inflammatory bowel disease and to explore the underlying mechanisms of their actions. Among the selected lactobacillus strains, Lactobacillus casei Lbs2 (MTCC5953) significantly suppressed lipopolysaccharide-induced pro-inflammatory cytokine (TNF-alpha, IL-6) secretion. Both live and heat-killed Lbs2 polarized Th0 cells to T-regulatory (Treg) cells in vitro, increased the frequency of FoxP3(+) Treg cells in the mesenteric lymph nodes (MLNs) and alleviated macroscopic and histopathological features of colitis in probiotic-fed mice. Moreover, the levels of IL-12, TNF-alpha and IL-17A were suppressed, while IL-10 and TGF-beta levels were augmented in the colonic tissues of Lbs2-treated mice. The induced Treg (iTreg) cells secreted IL-10 and TGF-beta and exerted suppressive effects on the proliferation of effector T-cells. Adoptive transfer of iTreg cells ameliorated the disease manifestations of murine colitis and suppressed the levels of TNF-alpha and IL-17A. Finally, Lbs2 effects were mediated by Toll-like receptor 2 (TLR2) activation on the dendritic cells. This study identified live and heat-killed Lbs2 as putative therapeutic candidates against IBD and highlighted their Toll-like receptor 2-dependent immunomodulatory and regulatory function. PMID:27107798

  6. The expression of Toll-like receptor 4, 7 and co-receptors in neurochemical sub-populations of rat trigeminal ganglion sensory neurons.

    Helley, M P; Abate, W; Jackson, S K; Bennett, J H; Thompson, S W N

    2015-12-01

    The recent discovery that mammalian nociceptors express Toll-like receptors (TLRs) has raised the possibility that these cells directly detect and respond to pathogens with implications for either direct nociceptor activation or sensitization. A range of neuronal TLRs have been identified, however a detailed description regarding the distribution of expression of these receptors within sub-populations of sensory neurons is lacking. There is also some debate as to the composition of the TLR4 receptor complex on sensory neurons. Here we use a range of techniques to quantify the expression of TLR4, TLR7 and some associated molecules within neurochemically-identified sub-populations of trigeminal (TG) and dorsal root (DRG) ganglion sensory neurons. We also detail the pattern of expression and co-expression of two isoforms of lysophosphatidylcholine acyltransferase (LPCAT), a phospholipid remodeling enzyme previously shown to be involved in the lipopolysaccharide-dependent TLR4 response in monocytes, within sensory ganglia. Immunohistochemistry shows that both TLR4 and TLR7 preferentially co-localize with transient receptor potential vallinoid 1 (TRPV1) and purinergic receptor P2X ligand-gated ion channel 3 (P2X3), markers of nociceptor populations, within both TG and DRG. A gene expression profile shows that TG sensory neurons express a range of TLR-associated molecules. LPCAT1 is expressed by a proportion of both nociceptors and non-nociceptive neurons. LPCAT2 immunostaining is absent from neuronal profiles within both TG and DRG and is confined to non-neuronal cell types under naïve conditions. Together, our results show that nociceptors express the molecular machinery required to directly respond to pathogenic challenge independently from the innate immune system. PMID:26434622

  7. Live Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis activate the inflammatory response trhough Toll-like receptors 2, 4, and 9 in species-specific patterns

    Mogensen, T.H.; Paludan, Søren Riis; Kilian, Mogens;

    2006-01-01

    activation by live bacteria. Here, we demonstrate that live Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis, the three principal causes of bacterial meningitis, use distinct sets of TLRs to trigger the inflammatory response. Using human embryonic kidney 293 cell lines....... meningitidis in cells expressing TLR2, -4, or -9. It is interesting that the ability of S. pneumoniae and N. meningitidis to activate TLR9 was severely attenuated when bacteria had been heat-inactivated prior to stimulation of the cells. In human peripheral blood mononuclear cells, we blocked TLR2, -4, or -9...... infection with live pathogens may lead to activation of PRR not targeted by inactivated bacteria....

  8. Respiratory epithelial cells require Toll-like receptor 4 for induction of Human β-defensin 2 by Lipopolysaccharide

    McElvaney Noel

    2005-10-01

    Full Text Available Abstract Background The respiratory epithelium is a major portal of entry for pathogens and employs innate defense mechanisms to prevent colonization and infection. Induced expression of human β-defensin 2 (HBD2 represents a direct response by the epithelium to potential infection. Here we provide evidence for the critical role of Toll-like receptor 4 (TLR4 in lipopolysaccharide (LPS-induced HBD2 expression by human A549 epithelial cells. Methods Using RTPCR, fluorescence microscopy, ELISA and luciferase reporter gene assays we quantified interleukin-8, TLR4 and HBD2 expression in unstimulated or agonist-treated A549 and/or HEK293 cells. We also assessed the effect of over expressing wild type and/or mutant TLR4, MyD88 and/or Mal transgenes on LPS-induced HBD2 expression in these cells. Results We demonstrate that A549 cells express TLR4 on their surface and respond directly to Pseudomonas LPS with increased HBD2 gene and protein expression. These effects are blocked by a TLR4 neutralizing antibody or functionally inactive TLR4, MyD88 and/or Mal transgenes. We further implicate TLR4 in LPS-induced HBD2 production by demonstrating HBD2 expression in LPS non-responsive HEK293 cells transfected with a TLR4 expression plasmid. Conclusion This data defines an additional role for TLR4 in the host defense in the lung.

  9. Acute phase serum amyloid A induces proinflammatory cytokines and mineralization via toll-like receptor 4 in mesenchymal stem cells

    Regina Ebert

    2015-07-01

    Full Text Available The role of serum amyloid A (SAA proteins, which are ligands for toll-like receptors, was analyzed in human bone marrow-derived mesenchymal stem cells (hMSCs and their osteogenic offspring with a focus on senescence, differentiation and mineralization. In vitro aged hMSC developed a senescence-associated secretory phenotype (SASP, resulting in enhanced SAA1/2, TLR2/4 and proinflammatory cytokine (IL6, IL8, IL1β, CXCL1, CXCL2 expression before entering replicative senescence. Recombinant human SAA1 (rhSAA1 induced SASP-related genes and proteins in MSC, which could be abolished by cotreatment with the TLR4-inhibitor CLI-095. The same pattern of SASP-resembling genes was stimulated upon induction of osteogenic differentiation, which is accompanied by autocrine SAA1/2 expression. In this context additional rhSAA1 enhanced the SASP-like phenotype, accelerated the proinflammatory phase of osteogenic differentiation and enhanced mineralization. Autocrine/paracrine and rhSAA1 via TLR4 stimulate a proinflammatory phenotype that is both part of the early phase of osteogenic differentiation and the development of senescence. This signaling cascade is tightly involved in bone formation and mineralization, but may also propagate pathological extraosseous calcification conditions such as calcifying inflammation and atherosclerosis.

  10. TOLL-LIKE RECEPTORS (TLR 2 AND 4 EXPRESSION OF KERATINOCYTES FROM PATIENTS WITH LOCALIZED AND DISSEMINATED DERMATOPHYTOSIS

    Cristiane Beatriz de Oliveira

    2015-02-01

    Full Text Available There are few studies on the role of innate immune response in dermatophytosis. An investigation was conducted to define the involvement of Toll-Like Receptors (TLRs 2 and 4 in localized (LD and disseminated (DD dermatophytosis due to T. rubrum. Fifteen newly diagnosed patients, eight patients with LD and seven with DD, defined by involvement of at least three body segments were used in this study. Controls comprised twenty skin samples from healthy individuals undergoing plastic surgery. TLR2 and TLR4 were quantified in skin lesions by immunohistochemistry. A reduced expression of TLR4 in the lower and upper epidermis of both LD and DD patients was found compared to controls; TLR2 expression was preserved in the upper and lower epidermis of all three groups. As TLR4 signaling induces the production of inflammatory cytokines and neutrophils recruitment, its reduced expression likely contributed to the lack of resolution of the infection and the consequent chronic nature of the dermatophytosis. As TLR2 expression acts to limit the inflammatory process and preserves the epidermal structure, its preserved expression may also contribute to the persistent infection and limited inflammation that are characteristic of dermatophytic infections.

  11. Identification and characterization of toll-like receptors (TLRs) in the Chinese tree shrew (Tupaia belangeri chinensis).

    Yu, Dandan; Wu, Yong; Xu, Ling; Fan, Yu; Peng, Li; Xu, Min; Yao, Yong-Gang

    2016-07-01

    In mammals, the toll-like receptors (TLRs) play a major role in initiating innate immune responses against pathogens. Comparison of the TLRs in different mammals may help in understanding the TLR-mediated responses and developing of animal models and efficient therapeutic measures for infectious diseases. The Chinese tree shrew (Tupaia belangeri chinensis), a small mammal with a close relationship to primates, is a viable experimental animal for studying viral and bacterial infections. In this study, we characterized the TLRs genes (tTLRs) in the Chinese tree shrew and identified 13 putative TLRs, which are orthologs of mammalian TLR1-TLR9 and TLR11-TLR13, and TLR10 was a pseudogene in tree shrew. Positive selection analyses using the Maximum likelihood (ML) method showed that tTLR8 and tTLR9 were under positive selection, which might be associated with the adaptation to the pathogen challenge. The mRNA expression levels of tTLRs presented an overall low and tissue-specific pattern, and were significantly upregulated upon Hepatitis C virus (HCV) infection. tTLR4 and tTLR9 underwent alternative splicing, which leads to different transcripts. Phylogenetic analysis and TLR structure prediction indicated that tTLRs were evolutionarily conserved, which might reflect an ancient mechanism and structure in the innate immune response system. Taken together, TLRs had both conserved and unique features in the Chinese tree shrew. PMID:26923770

  12. Phospholipid Scramblase 1 regulates Toll-like receptor 9-mediated type Ⅰ interferon production in plasmacytoid dendritic cells

    Amjad H Talukder; Musheng Bao; Tae Whan Kim; Valeria Facchinetti; Shino Hanabuchi; Laura Bover; Tomasz Zal; Yong-Jun Liu

    2012-01-01

    Toll-like receptor 9 (TLR9) senses microbial DNA in the endosomes of plasmacytoid dendritic cells (pDCs) and triggers MyD88-dependent type 1 interferon (IFN) responses.To better understand TLR9 biology in pDCs,we established a yeast two-hybrid library for the identification of TLR9-interacting proteins.Here,we report that an IFN-inducible protein,phospholipid scramblase 1 (PLSCR1),interacts with TLR9 in pDCs.Knockdown of PLSCR1 expression by siRNA in human pDC cell line led to a 60-70% reduction of IFN-α responses following CpG-ODN (oligodeoxynucleotide) stimulation.Primary pDCs from PLSCR1-deficient mice produced lower amount of type 1 IFN than pDCs from the wild-type mice in response to CpG-ODN,herpes simplex virus and influenza A virus.Following CpG-A stimulation,there were much lower amounts of TLR9 in the early endosomes together with CpG-A in pDCs from PLSCRl-deficient mice.Our study demonstrates that PLSCR1 is a TLR9-interacting protein that plays an important role in pDC's type 1 IFN responses by regulating TLR9 trafficking to the endosomal compartment.

  13. Hypoxia regulates Toll-like receptor-9 expression and invasive function in human brain cancer cells in vitro

    SANDHOLM, JOUKO; TUOMELA, JOHANNA; KAUPPILA, JOONAS H.; HARRIS, KEVIN W.; GRAVES, DAVID; SELANDER, KATRI S.

    2014-01-01

    Toll-like receptor-9 (TLR9) is a cellular DNA sensor of the innate immune system. TLR9 is widely expressed in a number of tumors, including brain cancer; however, little is known regarding its regulation and involvement in cancer pathophysiology. The present study demonstrated that hypoxia upregulates and downregulates TLR9 expression in human brain cancer cells in vitro, in a cell-specific manner. In addition, hypoxia-induced TLR9 upregulation was associated with hypoxia-induced invasion; however, such invasion was not detected in cells where hypoxia had suppressed TLR9 expression. Furthermore, suppression of TLR9 expression through TLR9 siRNA resulted in an upregulation of matrix metalloproteinase (MMP)-2, -9 and -13 and tissue inhibitor of matrix metalloproteinases-3 (TIMP-3) mRNA, and a decreased invasion of cells in normoxia, in a cell-specific manner. In cells where hypoxia induced TLR9 expression, TLR9 expression and invasion were reduced by TLR9 siRNA. The decreased invasion observed in hypoxia was associated with the decreased expression of the MMPs and a concomitant increase in TIMP-3 expression. In conclusion, hypoxia regulates the invasion of brain cancer cells in vitro in a TLR9-dependent manner, which is considered to be associated with a complex expression pattern of TLR9-regulated mediators and inhibitors of invasion. PMID:24959259

  14. Association between Toll-like receptor 9 gene polymorphisms and risk of bacterial meningitis in a Chinese population.

    Wang, X H; Shi, H P; Li, F J

    2016-01-01

    We determined whether two common single nucleotide polymorphisms (SNPs) in the Toll-like receptor 9 gene (TLR9) (TLR9+2848 rs352140 and TLR9-1237 rs5743836) influenced susceptibility to bacterial meningitis in a Chinese population. The study comprised 126 patients with bacterial meningitis and 252 control subjects, all of whom were recruited from the Tuberculosis Hospital of Shanxi Province. Genotyping of TLR9+2848 rs352140 and TLR9-1237 rs5743836 was performed by polymerase chain reaction coupled with restriction fragment length polymorphism. Using logistic regression analysis, we found that individuals with the AA genotype were associated with an increased risk of bacterial meningitis compared with those with the GG genotype (OR = 0.43, 95%CI = 0.19-0.95; P = 0.03). In a recessive model, the AA genotype was correlated with an elevated risk of bacterial meningitis compared with the GG+GA genotype (OR = 0.49, 95%CI = 0.22-0.99; P = 0.04). However, no significant differences were observed in the association between the TLR9-1237 rs5743836 polymorphism and the risk of bacterial meningitis in the codominant, dominant, or recessive models. In conclusion, the results of our study suggest an association between the TLR9+2848 polymorphism and a reduced risk of bacterial meningitis in the codominant and recessive models. PMID:27525854

  15. Cotinine inhibits the pro-inflammatory response initiated by multiple cell surface Toll-like receptors in monocytic THP cells

    Bagaitkar Juhi

    2012-11-01

    Full Text Available Abstract Background The primary, stable metabolite of nicotine [(S-3-(1-methyl-2-pyrrolidinyl pyridine] in humans is cotinine [(S-1-methyl-5-(3-pyridinyl-2-pyrrolidinone]. We have previously shown that cotinine exposure induces convergence and amplification of the GSK3β-dependent PI3 kinase and cholinergic anti-inflammatory systems. The consequence is reduced pro-inflammatory cytokine secretion by human monocytes responding to bacteria or LPS, a TLR4 agonist. Findings Here we show that cotinine-induced inflammatory suppression may not be restricted to individual Toll-like receptors (TLRs. Indeed, in monocytic cells, cotinine suppresses the cytokine production that is normally resultant upon agonist-specific engagement of all of the major surface exposed TLRs (TLR 2/1; 2/6; 4 and 5, although the degree of suppression varies by TLR. Conclusions These results provide further mechanistic insight into the increased susceptibility to multiple bacterial infections known to occur in smokers. They also establish THP-1 cells as a potentially suitable model with which to study the influence of tobacco components and metabolites on TLR-initiated inflammatory events.

  16. Polymeric Structure and Host Toll-like Receptor 4 Dictate Immunogenicity of NY-ESO-1 Antigen in Vivo*

    Liu, Yanan; Tian, Xiaoli; Leitner, Wolfgang W.; Aldridge, Michael E.; Zheng, Junying; Yu, Zhiya; Restifo, Nicholas P.; Weiss, Richard; Scheiblhofer, Sandra; Xie, Chong; Sun, Ren; Cheng, Genhong; Zeng, Gang

    2011-01-01

    In search of intrinsic factors that contribute to the distinctively strong immunogenicity of a non-mutated cancer/testis antigen, we found that NY-ESO-1 forms polymeric structures through disulfide bonds. NY-ESO-1 binding to immature dendritic cells was dependent on its polymeric structure and involved Toll-like receptor-4 (TLR4) on the surface of immature dendritic cells in mouse and human. Gene gun-delivered plasmid encoding the wild-type NY-ESO-1 readily induced T cell-dependent antibody (Ab) responses in wild-type C57BL/10 mice but not TLR4-knock-out C57BL/10ScNJ mice. Disrupting polymeric structures of NY-ESO-1 by cysteine-to-serine (Cys-to-Ser) substitutions lead to diminished immunogenicity and altered TLR4-dependence in the induced Ab response. To demonstrate its adjuvant effect, NY-ESO-1 was fused with a major mugwort pollen allergen Art v 1 and a tumor-associated antigen, carbonic anhydrase 9. Plasmid DNA vaccines encoding the fusion genes generated robust immune responses against otherwise non-immunogenic targets in mice. Polymeric structure and TLR4 may play important roles in rendering NY-ESO-1 immunogenic and thus serve as a potent molecular adjuvant. NY-ESO-1 thus represents the first example of a cancer/testis antigen that is a also damage-associated molecular pattern. PMID:21900253

  17. Regulation of humoral and cellular gut immunity by lamina propria dendritic cells expressing Toll-like receptor 5.

    Uematsu, Satoshi; Fujimoto, Kosuke; Jang, Myoung Ho; Yang, Bo-Gie; Jung, Yun-Jae; Nishiyama, Mika; Sato, Shintaro; Tsujimura, Tohru; Yamamoto, Masafumi; Yokota, Yoshifumi; Kiyono, Hiroshi; Miyasaka, Masayuki; Ishii, Ken J; Akira, Shizuo

    2008-07-01

    The intestinal cell types responsible for defense against pathogenic organisms remain incompletely characterized. Here we identify a subset of CD11c(hi)CD11b(hi) lamina propria dendritic cells (LPDCs) that expressed Toll-like receptor 5 (TLR5) in the small intestine. When stimulated by the TLR5 ligand flagellin, TLR5(+) LPDCs induced the differentiation of naive B cells into immunoglobulin A-producing plasma cells by a mechanism independent of gut-associated lymphoid tissue. In addition, by a mechanism dependent on TLR5 stimulation, these LPDCs promoted the differentiation of antigen-specific interleukin 17-producing T helper cells and type 1 T helper cells. Unlike spleen DCs, the LPDCs specifically produced retinoic acid, which, in a dose-dependent way, supported the generation and retention of immunoglobulin A-producing cells in the lamina propria and positively regulated the differentiation interleukin 17-producing T helper cells. Our findings demonstrate unique properties of LPDCs and the importance of TLR5 for adaptive immunity in the intestine. PMID:18516037

  18. Role of toll-like receptors 3, 4 and 7 in cellular uptake and response to titanium dioxide nanoparticles

    Chen, Peng; Kanehira, Koki; Taniguchi, Akiyoshi

    2013-02-01

    Innate immune response is believed to be among the earliest provisional cellular responses, and mediates the interactions between microbes and cells. Toll-like receptors (TLRs) are critical to these interactions. We hypothesize that TLRs also play an important role in interactions between nanoparticles (NPs) and cells, although little information has been reported concerning such an interaction. In this study, we investigated the role of TLR3, TLR4 and TLR7 in cellular uptake of titanium dioxide NP (TiO2 NP) agglomerates and the resulting inflammatory responses to these NPs. Our data indicate that TLR4 is involved in the uptake of TiO2 NPs and promotes the associated inflammatory responses. The data also suggest that TLR3, which has a subcellular location distinct from that of TLR4, inhibits the denaturation of cellular protein caused by TiO2 NPs. In contrast, the unique cellular localization of TLR7 has middle-ground functional roles in cellular response after TiO2 NP exposure. These findings are important for understanding the molecular interaction mechanisms between NPs and cells.

  19. Role of toll-like receptors 3, 4 and 7 in cellular uptake and response to titanium dioxide nanoparticles

    Peng Chen, Koki Kanehira and Akiyoshi Taniguchi

    2013-01-01

    Full Text Available Innate immune response is believed to be among the earliest provisional cellular responses, and mediates the interactions between microbes and cells. Toll-like receptors (TLRs are critical to these interactions. We hypothesize that TLRs also play an important role in interactions between nanoparticles (NPs and cells, although little information has been reported concerning such an interaction. In this study, we investigated the role of TLR3, TLR4 and TLR7 in cellular uptake of titanium dioxide NP (TiO2 NP agglomerates and the resulting inflammatory responses to these NPs. Our data indicate that TLR4 is involved in the uptake of TiO2 NPs and promotes the associated inflammatory responses. The data also suggest that TLR3, which has a subcellular location distinct from that of TLR4, inhibits the denaturation of cellular protein caused by TiO2 NPs. In contrast, the unique cellular localization of TLR7 has middle-ground functional roles in cellular response after TiO2 NP exposure. These findings are important for understanding the molecular interaction mechanisms between NPs and cells.

  20. Toll-like receptor 5 (TLR5), IL-1β secretion, and asparagine endopeptidase are critical factors for alveolar macrophage phagocytosis and bacterial killing.

    Descamps, Delphyne; Mathieu, Le Gars; Balloy, Viviane; Diane, Barbier; Sophia, Maschalidi; Mira, Tohme; Chignard, Michel; Ramphal, Reuben; Bénédicte, Manoury; Sallenave, Jean-Michel

    2012-01-01

    A deficit in early clearance of Pseudomonas aeruginosa (P. aeruginosa) is crucial in nosocomial pneumonia and in chronic lung infections. Few studies have addressed the role of Toll-like receptors (TLRs), which are early pathogen associated molecular pattern receptors, in pathogen uptake and clearance by alveolar macrophages (AMs). Here, we report that TLR5 engagement is crucial for bacterial clearance by AMs in vitro and in vivo because unflagellated P. aeruginosa or different mutants defect...